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Ultimate S’mores Layer Cake: A Decadent Homemade Delight
Prepare to embark on a culinary journey that brings the beloved campfire classic indoors with this truly ultimate S’mores Layer Cake. This show-stopping dessert captures all the nostalgic flavors of roasted marshmallows, rich chocolate, and crunchy graham crackers, meticulously layered into an exquisite cake. It features an incredibly soft and moist chocolate cake, enveloped in a luxurious silky chocolate buttercream, generously topped with fluffy homemade marshmallow fluff, and finished with delightful crushed cookies. Perfect for summer gatherings, birthday celebrations, or simply indulging your sweet tooth, this S’mores-inspired layer cake is a fun project to make and guarantees a flavor combination that never disappoints.
Every bite of this S’mores Layer Cake is a symphony of textures and tastes. The tender chocolate cake melts in your mouth, providing a rich base. The velvety smooth chocolate buttercream adds another layer of deep cocoa flavor, while the pillowy marshmallow fluff brings that signature sticky-sweetness. The crushed cookies, reminiscent of graham crackers, offer a satisfying crunch that ties all the elements together. It’s more than just a cake; it’s an experience, transforming simple ingredients into a truly unforgettable dessert that will leave everyone craving another slice.
This recipe is designed to guide you through each step, ensuring a successful and utterly delicious outcome. From baking the perfect chocolate cake layers to creating the cloud-like marshmallow fluff and assembling your masterpiece, you’ll find joy in every stage of the process. While this cake is truly a labor of love, the incredible taste and stunning presentation are well worth the effort. Get ready to impress your family and friends with a dessert that redefines the classic s’mores experience.
For those who adore rich, multi-layered desserts, explore more of our decadent cake recipes. You might love our Biscoff Cake with its spiced cookie flavor, the vibrant and citrusy Chocolate Orange Cake, or the delicate and sophisticated Raspberry Pistachio Cake.
Crafting the Perfect Chocolate Cake Layers
The foundation of any great layer cake is its sponge, and for this S’mores Layer Cake, we’re making a rich, moist, and incredibly tender chocolate cake. Achieving perfect cake layers is simpler than you might think with a few key steps and attention to detail. This recipe ensures a robust chocolate flavor and a beautiful crumb structure that will hold up wonderfully to the other luscious fillings.
Begin by preheating your oven to 175ºC (350ºF) for conventional baking. This allows the oven to reach and maintain the correct temperature, which is crucial for even baking. Prepare three 20 cm (8-inch) baking pans by lining their bottoms with parchment paper and greasing the sides. This prevents sticking and ensures your cake layers release easily after baking.
Next, boil the specified amount of water and set it aside to cool slightly. While it doesn’t need to be completely cold, allowing it to cool a bit ensures it won’t cook your eggs when combined with the wet ingredients. In a large mixing bowl, meticulously sift together all your dry ingredients: all-purpose flour, granulated sugar, unsweetened cocoa powder, instant espresso powder (which intensifies the chocolate flavor without making the cake taste like coffee), baking powder, baking soda, and salt. Sifting is vital here as it removes any lumps and aerates the mixture, contributing to a lighter, more uniform cake crumb. Give the sifted dry ingredients a good whisk to ensure they are thoroughly combined.
In a separate, larger mixing bowl, combine all the wet ingredients. This includes room temperature buttermilk (which reacts with the baking soda to create a tender cake), vegetable oil, large room temperature eggs, and vanilla extract. Incorporate the slightly cooled boiled water into this mixture. Using a hand whisk, gently combine these ingredients until just blended. The key here is not to overmix, especially the eggs, as overmixing can develop too much gluten and result in a tougher cake. The mixture should be smooth but not overly frothy.
Now, gradually pour the wet mixture into the dry ingredients. Stir gently, just until everything is combined and no dry flour streaks remain. Avoid vigorous mixing to maintain the cake’s delicate texture. The batter should be smooth and pourable. Divide the batter evenly among your three prepared 20 cm baking tins. Even distribution is important for layers of consistent thickness. Bake for approximately 22-25 minutes, or until a cake tester inserted into the center of a cake comes out clean. This indicates they are fully baked.
Once baked, remove the cakes from the oven and let them cool in their tins on a wire cooling rack for about 5 minutes. This brief cooling period helps the cakes firm up before handling. After 5 minutes, carefully invert the cakes onto the cooling rack, remove the parchment paper, and allow them to cool completely. Fully cooled cakes are essential before frosting, as warm cakes will melt your buttercream and compromise the structure of your S’mores masterpiece.
Whipping Up Silky Smooth Chocolate Buttercream
No S’mores cake would be complete without a generous layer of rich, smooth chocolate buttercream. This recipe delivers a luxurious, stable buttercream that’s easy to work with and packed with intense chocolate flavor. The secret lies in the quality of ingredients and careful temperature control.
Start by preparing your chocolate ganache component for the buttercream. Melt the dark chocolate and heavy cream together using a bain-marie (double boiler) or in the microwave. If using the microwave, heat in 30-second intervals, stirring well after each, until smooth and fully combined. It’s crucial to let this ganache cool down slightly before adding it to the butter; it should be lukewarm, not hot, to prevent melting the butter and creating a greasy buttercream. Set it aside while you begin with the butter.
For the butter, take it out of the fridge about 10-15 minutes before you plan to start mixing. This allows it to soften slightly to a cool room temperature, making it easier to cream without being too soft. Cut the butter into cubes for more even creaming. In a separate bowl, sift your powdered sugar and unsweetened Dutch-process cocoa powder together. Sifting prevents lumps and ensures a smooth buttercream texture.
In your stand mixer fitted with the paddle attachment, cream the cubed butter on medium speed for about 2 minutes. This aerates the butter, making it light and fluffy. Scrape down the sides of the bowl to ensure all butter is incorporated, then mix for another minute. Add the slightly cooled melted dark chocolate mixture to the creamed butter and mix on low speed until fully incorporated. Again, scrape down the sides of the bowl to ensure a uniform mixture. It’s important that the chocolate is not too hot at this stage to avoid a soupy buttercream.
With the mixer on low speed, gradually add the sifted powdered sugar and cocoa powder in three portions. Mix thoroughly after each addition until it’s fully incorporated before adding the next. This prevents a cloud of sugar from erupting in your kitchen and ensures a smooth texture. Once all additions are made, scrape down the sides of the bowl and continue mixing on low to medium speed for another 2 minutes. This final mixing step helps to make the buttercream extra smooth and creamy.
Once you’ve achieved a wonderfully smooth consistency, take the bowl off the stand mixer. Using a rubber spatula or a wooden spoon, beat the buttercream vigorously by hand for a minute or two. This manual step is incredibly effective at removing any trapped air bubbles, resulting in an exceptionally silky buttercream that’s a dream to spread and pipe.
PRO TIP for Buttercream Consistency: If your chocolate ganache cools too much and forms chocolate bits in your buttercream, don’t despair! Place the entire butter/chocolate mixture in the microwave for brief 15-second bursts, stirring in between, until the chocolate is just melted and combined with the butter, but without melting the butter itself. Then proceed with adding the powdered sugar and cocoa powder as instructed. If your finished buttercream feels too soft (perhaps due to a warm kitchen), simply pop it into the fridge for about 30 minutes to firm up. After chilling, give it another quick mix by hand or with the stand mixer until it returns to a perfect, workable consistency. Your silky chocolate buttercream is now ready for action!
Creating Cloud-Like Marshmallow Fluff
The star component of any S’mores treat is the marshmallow, and for this cake, we’re making a glorious homemade marshmallow fluff that’s light, airy, and bursting with vanilla flavor. This Swiss meringue-style marshmallow fluff is more stable than traditional Italian meringue and holds its shape beautifully for piping.
Before you begin, ensure your mixing bowl and whisk attachment for your stand mixer are impeccably clean and free of any grease. Even a tiny trace of fat can prevent egg whites from whipping up properly. This is a critical step for successful meringue.
In the clean mixing bowl of your stand mixer, combine the egg whites, granulated sugar, and glucose syrup (or corn syrup). Glucose syrup adds elasticity and helps prevent sugar crystallization. Place this bowl over a pot of simmering water, creating a double boiler. Crucially, ensure the bottom of the mixing bowl does not touch the simmering water. Using the whisk attachment or a hand whisk, continuously stir the mixture over the heat. Your goal is to gently warm the mixture and dissolve the sugar granules completely. You can test this by rubbing a small amount of the mixture between your fingers; if it feels smooth with no grittiness, the sugar is dissolved.
Once the sugar has dissolved and the mixture is warm to the touch (around 70°C or 160°F), immediately remove the bowl from the heat and attach it to your stand mixer. With the whisk attachment, begin whipping the mixture on high speed. Continue mixing for 5-6 minutes, or until the meringue becomes incredibly stiff, glossy, and the mixing bowl no longer feels warm but has reached room temperature. The meringue should form firm peaks that hold their shape. Finally, add the vanilla paste and mix it in just until combined. Vanilla paste provides a richer, more authentic vanilla flavor compared to extract, and you’ll see those lovely specks of vanilla bean.
Once ready, transfer your cloud-like marshmallow fluff into a piping bag. This will make it significantly easier and neater to apply evenly between your cake layers, creating that iconic S’mores look and taste.
Assembling Your S’mores Masterpiece
The moment of truth has arrived! Assembling your S’mores Layer Cake is where all your hard work comes together to create a truly spectacular dessert. This process involves careful layering to ensure a stable, beautiful, and delicious cake.
IMPORTANT NOTE: For this recipe, it’s crucial that once assembled, this cake is enjoyed within a few hours, preferably immediately. The marshmallow fluff, while delicious, will slowly deflate over time, altering its texture and compromising the overall freshness. Plan to serve this cake soon after its final touches for the best and most delicious result.
First, ensure your chocolate cake layers are completely cool. If needed, use a serrated knife or a cake leveler to trim the tops of your cake layers so they are perfectly flat and of even height. This creates a stable foundation for stacking. Place your first leveled sponge layer onto your chosen serving dish or a cake board on a turntable if you have one. A turntable makes decorating much easier, but it’s certainly not essential; you can easily decorate a beautiful cake without one.
Next, spoon a small dollop of the chocolate buttercream onto the center of the first cake layer. Using an offset spatula, spread the buttercream evenly across the surface, creating a smooth, level layer. Transfer a portion of your remaining chocolate buttercream into a piping bag fitted with a round tip (or simply snip off the corner of the bag). Pipe a sturdy, wide border of buttercream around the very edge of the cake layer. This “dam” is crucial; it acts as a barrier to prevent the soft marshmallow fluff from oozing out the sides once the next layer is added.
Carefully pipe or spoon a generous amount of the marshmallow fluff inside the buttercream dam. Spread it gently to fill the space. Now, take your digestive cookies and crush them into coarse crumbs. Sprinkle a generous amount of these crushed cookies evenly over the marshmallow fluff. This adds that essential “graham cracker” crunch and flavor. Gently place the second chocolate sponge layer on top, aligning it perfectly. Repeat the process: a dollop of buttercream, spread it, pipe a buttercream dam, fill with marshmallow fluff, and sprinkle with crushed cookies.
Finally, position the last chocolate sponge layer on top. Apply a thin layer of chocolate buttercream over the entire cake – sides and top. This is known as a “crumb coat,” and its purpose is to trap any loose crumbs, preventing them from mixing into your final layer of frosting. Once crumb-coated, place the cake in the freezer for about 30 minutes. This quick chill allows the crumb coat to firm up, making it significantly easier to apply the final, smooth layer of buttercream without pulling up crumbs.
After 30 minutes, remove the cake from the freezer. Apply the remaining chocolate buttercream evenly over the top and sides of the cake. Use an offset spatula or a cake scraper to smooth the sides and top, achieving a clean and professional finish. For truly sharp edges, you can chill the cake again briefly. Once smoothed, place the cake back in the freezer for another 30 minutes to firm up the final buttercream layer. While it chills, prepare your chocolate ganache for the elegant drip decoration.
Decadent Chocolate Ganache Drip
For the stunning chocolate drip, you’ll need the following:
- 100 g dark chocolate (chopped, if not using chips)
- 100 g heavy cream
If you’re using a chocolate bar, finely chop the dark chocolate; chocolate chips melt more evenly but chopped chocolate works just as well. Heat the heavy cream in a small saucepan until it just comes to a boil. Immediately pour the hot cream over the chopped chocolate in a heatproof bowl. Let the mixture sit undisturbed for 2 minutes. This allows the heat from the cream to melt the chocolate. After 2 minutes, stir the mixture gently with a rubber spatula, starting from the center and working outwards, until it transforms into a smooth, glossy ganache. Allow it to cool slightly, but ensure it’s still pourable.
Take your chilled cake out of the fridge. Carefully pour the slightly cooled ganache over the top of the cake. Use an offset spatula to gently spread the ganache to the edges, allowing it to drip attractively down the sides. For a consistent drip effect, ensure the ganache is not too hot (which would make it run too much) or too cold (which would make it too thick to drip). Even out the top surface of the ganache for a polished look.
Finally, for the quintessential S’mores touch, decorate the top of your cake with large marshmallows. For that authentic campfire experience, use a kitchen blow torch to gently toast the marshmallows until they’re golden brown and slightly caramelized. Be cautious and keep the torch moving to prevent burning. Your masterpiece is now complete!
This ultimate S’mores Layer Cake is best enjoyed immediately to experience the fresh, fluffy marshmallow and perfectly balanced textures. Slice it, serve it, and watch the smiles light up the room!
Storage Tips for Your S’mores Layer Cake
Due to the delicate nature of the homemade marshmallow fluff, this S’mores Layer Cake is truly at its absolute best when enjoyed on the day it’s assembled. The marshmallow fluff, while delicious, will slowly lose its airy texture and deflate over time if stored. Therefore, we highly recommend planning to serve and consume this cake within a few hours of its completion for the most delightful experience. If you must store it for a very short period (e.g., overnight), cover it loosely with plastic wrap to prevent it from drying out and refrigerate. However, be aware that the marshmallow texture will change.
Other Layer Cake Recipes To Try
- Hot Chocolate Layer Cake with Marshmallow Buttercream and Chocolate Fudge Sauce
- Banoffee Cake
- 25 Best Summer Dessert Ideas
- Lemon Raspberry Cake
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S’mores Layer Cake
Pin Recipe
Equipment
- 3 x 20 cm baking pan
- Stand mixer with whisk and paddle attachments
- Piping bag
- Offset spatula
- Kitchen blow torch (optional, for toasting marshmallows)
Ingredients
CHOCOLATE CAKE LAYERS
- 260 g all-purpose flour
- 300 g sugar
- 75 g unsweetened cocoa powder
- 1 teaspoon instant espresso powder
- 1 teaspoon baking powder
- 1 ½ teaspoon baking soda
- 1 teaspoon salt
- 240 g buttermilk room temperature
- 110 g vegetable oil
- 3 large eggs room temperature
- 2 teaspoon vanilla extract
- 200 g boiling water
DARK CHOCOLATE BUTTERCREAM
- 300 g butter cool room temperature
- 200 g dark chocolate
- 100 g heavy cream
- 500 g powdered sugar
- 25 g unsweetened dutch process cocoa powder
MARSHMALLOW FLUFF
- 50 g egg whites
- 95 g granulated sugar
- 40 g glucose syrup or corn syrup
- ¼ teaspoon vanilla paste
- 100 g digestive cookies
GANACHE
- 100 g dark chocolate
- 100 g heavy cream
DECORATION
- a bag of marshmallows
Instructions
- IMPORTANT NOTE: For this recipe, it’s important that once it’s assembled it should be eaten within a few hours, preferably immediately, for the best and most delicious result, as the marshmallow fluff will slowly deflate and therefore change in texture.
DARK CHOCOLATE CAKE LAYERS
- Preheat the oven to 175ºC (350°F) conventional and prepare three 20 cm (8-inch) baking pans by lining the bottoms with parchment paper and greasing the sides.
- Boil the water and set aside to cool slightly while you prepare the other ingredients.200 g boiling water
- In a large bowl, sift all the dry ingredients together: flour, sugar, cocoa powder, espresso powder, baking powder, baking soda, and salt. Stir well to combine evenly.260 g all-purpose flour, 300 g sugar, 75 g unsweetened cocoa powder, 1 teaspoon instant espresso powder, 1 teaspoon baking powder, 1 ½ teaspoon baking soda, 1 teaspoon salt
- In another mixing bowl, combine all the wet ingredients: buttermilk, vegetable oil, large eggs, vanilla extract, and the slightly cooled boiled water. Whisk them together gently until just combined. Avoid overmixing the eggs.240 g buttermilk, 110 g vegetable oil, 3 large eggs, 2 teaspoon vanilla extract
- Slowly pour the wet ingredients into the dry, stirring gently until the batter is smooth and no lumps remain. Do not overmix.
- Divide the cake batter evenly into the three prepared 20 cm baking tins and bake for 22-25 minutes, or until a cake tester inserted into the center comes out clean.
- Let the cakes cool in their tins on a cooling rack for 5 minutes. Then, gently remove them from the tins and allow them to cool completely on the rack before frosting.
DARK CHOCOLATE BUTTERCREAM
- Melt the dark chocolate and heavy cream together over a bain-marie or in the microwave (in 30-second intervals, stirring between). Let it cool down slightly to lukewarm; it’s important that it’s not hot when added to the butter.200 g dark chocolate, 100 g heavy cream
- Take the butter out of the fridge 10-15 minutes before starting. Cut the cool room temperature butter into cubes.300 g butter
- Sift the powdered sugar and unsweetened Dutch-process cocoa powder together.500 g powdered sugar, 25 g unsweetened dutch process cocoa powder
- In your stand mixer with the paddle attachment, cream the butter for 2 minutes on medium speed. Scrape down the bowl sides, mix 1 more minute. Add the cooled melted dark chocolate and mix until incorporated. Scrape down again. On low speed, add the sifted powdered sugar/cocoa powder in 3 portions, mixing until each is fully incorporated. Scrape the bowl and mix for 2 minutes on low/medium speed for a smooth consistency.
- Remove the bowl from the mixer and beat the buttercream well by hand with a rubber spatula to remove any air bubbles, ensuring a silky smooth texture. Set aside while making the marshmallow fluff.
- TIP: If the chocolate ganache cools too much and you end up with chocolate bits in your buttercream when adding it to the butter, place the butter/chocolate mixture in the microwave for 15 seconds at a time to gently melt the chocolate together with the butter without melting the butter itself. Then add the powdered sugar and cocoa powder as instructed. If the buttercream becomes too soft, place it in the fridge to cool for 30 minutes, then mix again before use.
MARSHMALLOW FLUFF
- Ensure your mixing bowl and whisk are completely clean and free of any grease before starting.
- In the mixing bowl of your stand mixer, add the egg whites, granulated sugar, and glucose syrup. Place the bowl over a pot of simmering water (bain-marie), making sure the water does not touch the bottom of the bowl. Whisk constantly until the sugar granules have completely melted with the egg whites and the mixture is warm to the touch (smooth when rubbed between fingers).50 g egg whites, 95 g granulated sugar, 40 g glucose syrup or corn syrup
- Remove the bowl from the heat and immediately transfer it to your stand mixer. Whip on high speed for 5-6 minutes until the bowl feels room temperature and the fluff is stiff, glossy, and holds firm peaks. Add the vanilla paste and mix until just combined.¼ teaspoon vanilla paste
- Transfer the marshmallow fluff to a piping bag for easier and neater application on the cake.
ASSEMBLING
- Trim the tops of the chocolate cakes with a serrated knife to create even, flat layers. Place the first sponge layer on your serving dish or cake board on a turntable.
- Add a small dollop of chocolate buttercream to the center of the cake layer and spread it evenly with an offset spatula. Using a piping bag with buttercream, pipe a strong, wide border around the top edge of the cake. This dam prevents the marshmallow fluff from escaping.
- Pipe or spoon marshmallow fluff inside the buttercream border. Crush digestive cookies and sprinkle them generously over the marshmallow fluff. Place the next sponge layer on top and repeat the buttercream and marshmallow fluff process. Position the final sponge layer. Apply a thin layer of chocolate buttercream over the entire cake for a crumb coat, sealing in any loose crumbs. Place the cake in the freezer for 30 minutes to set.100 g digestive cookies
- Remove the cake from the freezer after 30 minutes. Apply the remaining buttercream in an even layer over the entire cake. Use a cake scraper or offset spatula to smooth the sides and top. Return the cake to the freezer for another 30 minutes to firm up. Meanwhile, prepare the ganache for decoration.
GANACHE & DECORATION
- Finely chop the dark chocolate if you are not using chocolate chips.100 g dark chocolate
- Heat the heavy cream to a boil and immediately pour it over the chopped chocolate. Let it sit for 2 minutes, then stir with a rubber spatula until smooth and glossy. Allow to cool slightly until pourable.100 g heavy cream
- Take the cold cake out of the freezer and pour the ganache over the top, guiding it with an offset spatula to create an attractive drip effect down the sides. Even out the top surface of the ganache.
- Lastly, decorate the top of the cake with large marshmallows. Use a kitchen blow torch to gently toast the marshmallows for a beautiful, caramelized effect.a bag of marshmallows
- Your ultimate S’mores Layer Cake is now ready to be enjoyed! Best served immediately for optimal texture and flavor.