Decadent Brownie and Nutella Mousse Cake: The Ultimate Hazelnut Chocolate Dessert Recipe
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Prepare to embark on a truly unforgettable dessert experience with this exquisite Brownie and Nutella Mousse Cake! If you’re a devoted fan of Nutella and crave an indulgence that harmonizes rich chocolate with nutty undertones, then this extraordinary cake is undoubtedly crafted for you. This masterpiece of a dessert layers a supremely fudgy brownie base, a delightful, subtly salted hazelnut praliné for that perfect crunch, a velvety smooth Nutella mousse, and is gracefully finished with a glossy, alluring cacao mirror glaze. Each component is meticulously designed to create a symphony of textures and flavors that will captivate your palate and leave you longing for another slice.
This Brownie and Nutella mousse cake isn’t just delicious; it’s a celebration of flavor and texture. The ingenious addition of the hazelnut praliné introduces an incredible textural contrast to the soft, fudgy brownie and the light, airy Nutella mousse. Its slight crunch and intense hazelnut flavor cut through the richness of the chocolate beautifully. When creating the praliné, using a powerful hand blender is key to achieving that perfectly smooth, spreadable consistency. I personally highly recommend a robust blender like a Bamix, which can transform toasted hazelnuts into a silky praliné in mere minutes. Remember to pause and scrape down the sides of your blender jar a few times during the process to ensure every last piece is incorporated. Adding a tiny pinch of salt to the hazelnut praliné is a small but crucial detail that elevates the entire cake. This touch of salt expertly balances the sweetness, preventing it from being overly cloying, and remarkably enhances all the deep, wonderful chocolate and hazelnut flavors present in each bite.
For crafting the elegant shape of this mousse cake, I opted for an eclipse silicone mold, which lends a sophisticated aesthetic. However, don’t let the specific mold limit your creativity! If an eclipse mold isn’t readily available, a standard 18 cm silicone mold will work just as beautifully to achieve a stunning round mousse cake. The key is to ensure your mold is silicone for easy demolding of the frozen cake.
If you’re looking to explore more delightful mousse cake creations after mastering this Nutella version, be sure to check out some of my other popular recipes. You might enjoy the harmonious blend of flavors in my Peanut Butter and Dark Chocolate Mousse Cake, or perhaps the sophisticated notes of a Chocolate, Coffee and Caramel Tart. For another classic combination, my Chocolate and Caramel Mousse Cake is always a crowd-pleaser.
Crafting the Perfect Fudgy Brownie Base
The foundation of this incredible dessert is a rich, fudgy brownie. Achieving the perfect brownie texture is crucial – moist, dense, and intensely chocolatey. Follow these steps carefully to ensure your brownie layer is everything it should be. The oven temperature is essential for a fudgy interior without overbaking.
Preheat your oven to 175°C (conventional heat). This ensures an even bake from the moment the batter enters the oven.
In a medium mixing bowl, melt the butter gently. Once melted, pour it into a larger mixing bowl. Add both granulated sugar and brown sugar, along with the vanilla extract. Use a hand whisk to combine these ingredients for about 30-60 seconds, until they are well integrated and the mixture starts to look slightly glossy. This initial mixing helps to dissolve the sugar and create that characteristic chewy brownie texture.
Next, crack in the large egg. Mix it into the butter and sugar mixture until just combined. Be careful not to overmix at this stage, as overmixing can lead to a tougher brownie.
In a separate bowl, whisk together your dry ingredients: all-purpose flour, unsweetened cocoa powder, and a pinch of salt. Sifting these together beforehand ensures there are no lumps and that they are evenly distributed.
Gradually add the dry ingredients to the wet batter. Using a spatula, gently fold the batter until it is just combined. Overmixing the flour will develop the gluten too much, resulting in a cake-like brownie rather than a fudgy one. Stop mixing as soon as no dry streaks of flour are visible.
Carefully pour the brownie batter into a 16 cm silicone mold. Use your spatula to smooth out the top, ensuring an even layer for consistent baking.
Bake for approximately 12-14 minutes. Brownies are prone to overbaking, so keep an eye on them. The edges should be set, but the center should still be slightly soft. Once baked, remove the mold from the oven and let it cool down for 5-10 minutes. Then, gently unmold the brownie from the silicone mold and place it on a wire rack to cool down completely. This prevents it from becoming soggy.
Creating the Irresistible Hazelnut Praliné Layer
The hazelnut praliné is a game-changer in this dessert, providing a delightful texture and an intensified nutty flavor. The process involves making a homemade caramel and blending it with toasted hazelnuts to create a uniquely crunchy yet smooth layer.
Begin by preheating your oven to 200ºC (conventional oven). Spread your hazelnuts on a baking sheet and toast them for about 5 minutes. Toasting brings out their natural oils and deepens their flavor. Once toasted, let them cool down completely. This step is crucial, as warm hazelnuts can affect the caramel.
To make the dry caramel, slowly melt the sugar over low heat in a small, heavy-bottomed pot. Resist the urge to stir constantly; let the sugar melt and caramelize on its own, swirling the pot occasionally if needed. It will transform into a beautiful amber color. Once the caramel reaches this rich hue, immediately remove the pot from the heat. Carefully add the cooled hazelnuts to the caramel and quickly fold them together using a heat-proof silicone spatula. Be extremely cautious as the caramel is very hot.
Immediately spread the hazelnut-caramel mixture thinly onto a silicone mat or a piece of baking paper. Allow it to cool down completely until it becomes hard and brittle. This can take some time, so be patient.
Once the hazelnut brittle is completely cooled and hardened, break it into smaller pieces. Transfer these pieces to a strong blender or food processor. Blend until the mixture becomes smooth and forms a creamy praliné. This process takes time and patience; initially, it will be powdery, then clumpy, and eventually, the oils from the hazelnuts will release, turning it into a fluid, smooth paste. Scrape down the sides of the blender as needed. As mentioned earlier, a powerful blender is paramount for a perfectly smooth praliné.
Retrieve your cooled brownie and place it back into the same 16 cm (clean) silicone mold. Pour the freshly made hazelnut praliné evenly over the brownie layer. Gently spread it to cover the entire surface. Place the mold in the freezer for a few hours, allowing the praliné to set firmly. This solidifies the layer and makes assembly much easier.
Crafting the Silky Nutella Mousse
The Nutella mousse is the star of this cake, offering a light, airy, and intensely flavorful hazelnut chocolate experience. Its smooth texture perfectly complements the fudgy brownie and crunchy praliné. Precision in technique ensures a stable yet delicate mousse.
First, prepare your gelatin sheets by blooming them in a bowl of cold water. This softens them and prepares them for dissolution.
Measure out the Greek yogurt and let it sit on your kitchen counter at room temperature. This helps it incorporate more smoothly with the other components. While it warms slightly, prepare the Nutella and heavy cream.
Meanwhile, gently heat 75g of the total 250g heavy cream in a small pot over medium heat. Watch it closely; you want it to just begin to slightly boil around the edges. Remove the pot from the heat immediately. Squeeze the excess water from the bloomed gelatin sheets and add them to the hot cream, stirring until the gelatin has completely dissolved. This hot cream will ensure the gelatin fully melts and integrates.
Pour this warm gelatin-infused heavy cream over the Nutella in a mixing bowl. Using a spatula, mix it together until it becomes a cohesive, smooth mixture. For an extra silky texture, use an immersion blender to blend the Nutella mixture until it’s perfectly smooth and free of any lumps.
Now, it’s time to combine the Nutella mixture with the Greek yogurt. Add the Nutella mixture to the Greek yogurt in three gradual parts, folding gently after each addition. This ensures a slow and even combination, preventing the yogurt from seizing or creating a lumpy texture.
In a separate, clean bowl, whip the remaining heavy cream until soft peaks form. Be careful not to over-whip it into stiff peaks, as this can make it difficult to fold into the Nutella mixture and result in a less airy mousse.
With a rubber spatula, gently fold the whipped cream into the Nutella and yogurt mixture. Do this in three parts, incorporating each addition fully but carefully, until the mousse is smooth, light, and uniformly combined. The goal is to retain as much air as possible for that signature mousse texture.
Grab your 18cm eclipse silicone mold (or your chosen 18cm silicone mold) and place a small, sturdy board or tray underneath it. This will make it significantly easier to transfer the mold with the delicate mousse into the freezer without deforming it. Pour the prepared Nutella mousse into the mold, filling it about two-thirds of the way.
Carefully retrieve the brownie layer (with the set praliné) from the freezer. Invert the brownie layer and gently place it into the center of the Nutella mousse, with the hazelnut praliné facing downwards into the mousse. This creates a beautiful, layered cross-section when the cake is sliced.
Finally, gently lift the entire mousse cake (still on its board) and transfer it to the freezer. It needs to set for a minimum of 6 hours, but for best results and easiest handling, leaving it overnight is highly recommended. This ensures the mousse is perfectly firm for glazing.
Achieving a Flawless Mirror Glaze and Elegant Decoration
The mirror glaze provides a stunning, professional finish to your mousse cake, while the decoration adds personal flair and extra texture. These final steps bring the entire dessert together into a show-stopping creation.
For the mirror glaze, begin by blooming the gelatin sheets in cold water, just as you did for the mousse. This ensures they are ready to be dissolved when needed.
Sift the cocoa powder over a bowl. This is critical to prevent lumps in your glaze, which would mar its smooth, reflective surface.
In a small pot, combine water, granulated sugar, and condensed milk. Stir these ingredients together and heat the mixture to a boil over medium heat. Once boiling, immediately remove the pot from the heat. Squeeze out any excess water from the bloomed gelatin sheets and add them to the hot liquid, stirring thoroughly until the gelatin has completely dissolved. The heat from the mixture will melt the gelatin effortlessly.
Pour the hot liquid mixture over the sifted cocoa powder. Hold the bowl at an angle while pouring the liquid down the edge. This technique helps to minimize the introduction of air bubbles, which can spoil the mirror-like finish of the glaze. With a rubber spatula, gently stir the cocoa powder and liquid together until the mixture is cohesive. Then, use an immersion blender to blend the glaze until it is perfectly smooth and uniform. Again, hold the immersion blender at an angle and keep it submerged to avoid creating more air bubbles. For storage or further cooling, pour the mirror glaze into a jug, again holding the jug at an angle to prevent additional bubbles.
Cover the surface of the glaze directly with a piece of cling film (plastic wrap). This prevents a skin from forming. Allow the glaze to cool down to a specific temperature range: between 33-34ºC. This is the optimal temperature for pouring, ensuring it flows smoothly and evenly over the frozen cake without being too thin or too thick.
While the glaze cools, prepare your glazing station. Line a baking tray with a piece of cling film or parchment paper to catch excess glaze. Place a sturdy cup upside down in the center of the tray; this will serve as the stand for your frozen cake, allowing the glaze to drip freely.
Once the mirror glaze has reached the desired temperature, take the mousse cake out of the freezer and carefully unmold it from the silicone form. Place the frozen cake on top of the inverted cup on your prepared tray.
Pour the mirror glaze evenly over the entire frozen cake, ensuring every surface is covered. Let it drip off naturally for a few minutes. Once the glaze has set (which happens quickly on the cold cake), use a small knife to carefully remove any glaze droplets hanging from the bottom edge of the cake. Then, using two offset spatulas, gently lift the glazed cake off the cup and transfer it to your chosen serving dish. Place the cake in the refrigerator to defrost for 3-4 hours before serving. This gradual defrosting allows the mousse to return to its ideal creamy texture.
CHOCOLATE DECORATION
To add a touch of elegance and extra chocolatey goodness, prepare some simple chocolate decorations. Temper your dark chocolate; this ensures it sets with a beautiful shine and a satisfying snap. Pour the tempered chocolate into a small piping bag. Snip a very small hole at the tip of the piping bag. Pipe the chocolate onto a few pieces of parchment paper in a gentle wave movement. Experiment with different sizes and shapes to create visual interest. Let these chocolate waves firm up completely at room temperature or in the refrigerator.
When you’re ready to serve your magnificent Brownie and Nutella Mousse Cake, take it out of the fridge. Carefully arrange a few of your chocolate waves on top of the cake. Complement this with some halved and roughly chopped hazelnuts for added texture and a sprinkle of edible gold dust for a luxurious shimmer. Store any leftover chocolate waves in an airtight container for future use – they make fantastic decorations for other desserts!
Storage Tips for Your Mousse Cake
To keep your Brownie and Nutella Mousse Cake tasting fresh and delicious, proper storage is essential. Store any leftover cake in an airtight container in the refrigerator. This will protect it from drying out and absorbing other odors from the fridge. For the best flavor and texture, it is recommended to enjoy the cake within 3-4 days of preparation. If you need to store it for longer, individual slices can be carefully wrapped in cling film and then foil, and frozen for up to 2-3 weeks. Thaw frozen slices in the refrigerator overnight before serving.
Discover More Mousse Cake Recipes To Try
If you’ve fallen in love with the elegance and flavor of mousse cakes, there’s a whole world of possibilities to explore! Expand your baking repertoire with these other fantastic mousse cake recipes, each offering a unique and delightful experience:
- Classic Chocolate Mousse Cake
- Strawberry and Pistachio Mousse Cake
- Peanut Butter Dark Chocolate Mousse Cake
- Raspberry and Rhubarb Mousse Layer Cake
Did you fall in love with this recipe? Make sure to leave a STAR REVIEW and share your delightful creation! Tag me on Instagram @juliemarieeats so I can see your beautiful bakes. For endless culinary inspiration and more amazing dessert ideas, don’t forget to follow me on Pinterest!
Decadent Brownie and Nutella Mousse Cake
Pin Recipe
Equipment
- 16 cm silicone mold
- 18 cm eclipse silicone mold from Silikomart (or similar 18cm round silicone mold)
- Strong hand blender or food processor
- Heat-proof silicone spatula
- Immersion blender
Ingredients
BROWNIE
- 75 g salted butter
- 50 g granulated sugar
- 50 g brown sugar
- 1 teaspoon vanilla extract
- 1 large egg
- 70 g all-purpose flour
- 20 g unsweetened cocoa powder
- Pinch of salt
HAZELNUT PRALINÉ
- 50 g hazelnuts
- 50 g granulated sugar
- Pinch of salt
NUTELLA CHOCOLATE MOUSSE
- 2 gelatin sheets
- 100 g Nutella chocolate
- 100 g greek yogurt
- 250 g heavy cream
MIRROR GLAZE
- 5 gelatin sheets
- 100 g water
- 100 g granulated sugar
- 200 g condensed milk
- 45 g cocoa powder
CHOCOLATE DECORATION
- 40 g dark chocolate
- Hazelnuts
- Edible gold dust
Instructions
BROWNIE
- Preheat the oven at 175°C conventional oven.
- Melt the butter. Pour the melted butter into a mixing bowl. Add the sugars and vanilla extract. Use a hand whisk and mix until combined, for about 30-60 seconds.
- Add the egg and mix until just combined.
- In a separate bowl mix together the flour, unsweetened cocoa powder, and salt.
- Add it to the wet batter and gently mix the batter until just combined.
- Pour the batter into a 16 cm silicon mold and smooth it out with the spatula.
- Bake for about 12-14 min. Once baked let, it cool down. After it’s cooled down for 5-10 min, gently take it out of the silicone mold and let it cool down completely.
HAZELNUT PRALINÉ
- Pre-heat the oven at 200ºC conventional oven. Toast the hazelnuts for 5 min. Once toasted, let them cool down completely.
- Make a dry caramel by slowly melting the sugar over low heat in a small pot until a nice amber color. Add the hazelnuts and fold them quickly together with a heat-proof silicone spatula. Be careful as it’s very warm. Spread it out on a silicone mat or baking paper. Let it cool down completely.
- Once completely cooled down, use a strong blender, and blend it until smooth.
- Place the brownie back into the same 16 cm (clean) silicone mold and pour the praliné on top of the brownie. Place it in the freezer to set, for a few hours.
NUTELLA MOUSSE
- Bloom the gelatin sheets in cold water.
- Weigh out the greek yogurt and let it sit on the kitchen counter while preparing the Nutella and heavy cream.
- Meanwhile, heat up 75g of the 250g heavy cream in a small pot on medium heat until it starts to slightly boil. Take the pot off the heat and add the gelatine sheet. Stir it in until the gelatine has dissolved.
- Pour the heated heavy cream over the Nutella and with a spatula mix it together until cohesive. Take an emersion blender and blend it until smooth.
- Add the Nutella mixture into the greek yogurt in 3 parts, to slowly combine the two mixtures.
- Whip the remaining heavy cream until soft peaks. With the rubber spatula, gently fold together the whipped cream in 3 parts with the Nutella mixture until smooth and combined. Take your 18cm eclipse silicone mold and place a small board under the silicone mold to make it easier to move the mousse into the freezer. Pour the mousse into the mold.
- Take the brownie out of the freezer and place the cake upside down, with the hazelnut praliné facing down into mousse, and place it in the center of the Nutella mousse.
- Gently lift the mousse cake into the freezer for a minimum of 6 hours or preferable overnight.
MIRROR GLAZE
- Bloom the gelatin sheets in cold water.
- Sift the cocoa powder over a bowl.
- In a small pot, stir together water, sugar, and condensed milk and heat to a boil. Then take it off the heat and add the gelatin sheets, squeezing the excess water off the gelatin, and stir it in.
- Hold the bowl at an angle and pour the hot liquid down the edge of the bowl to avoid creating air bubbles. With a rubber spatula gently stir the cocoa powder and liquid together until more cohesive. Then with an emersion blender, blend the glaze together until smooth. Pour the mirror glaze into a jug, holding the jug at an angle, to again avoid creating extra bubbles.
- Place a piece of cling film over the glaze, so it touches the surface of the glaze and allows the glaze to cool until it reaches a temperature between 33-34ºC.
- Prepare a baking tray with a piece of cling film. Place a cup upside down, for the cake to stand on.
- Once the glaze has reached the wanted temperature, take the mousse cake out of the freezer and out of the mold and place it on the cup.
- Pour the mirror glaze over the cake and let it drip off. Once set, remove any mirror glaze droplets hanging off the cake with a knife and lift the cake of the cup using two offset spatulas under the cake and gently lift it over to your serving dish. Place it in the fridge to defrost for 3-4 hours.
CHOCOLATE DECORATION
- Temper the dark chocolate. Pour it into a small piping bag. Take the piping bag and cut a small hole. Pipe the chocolate on a few pieces of parchment paper in a wave movement. Let them firm up.
- Once it ready, and you’re ready to serve, take the cake out of the fridge and gently add a few chocolate waves on the cake, as well as some halved and chopped hazelnuts and a little bit of edible gold dust. Save the other chocolate waves in an airtight container for decoration for other cakes.