Chocolate Mousse Cake is an indulgent layer cake recipe with 3 layers of chocolate cake, dark chocolate frosting, and rich chocolate mousse.
This incredible, showstopping, decadent Cake Recipe is a chocolate lover’s dream come true! The combination of Rich Chocolate Cake, Dark Chocolate Frosting, and fluffy chocolate mousse filling make it the ultimate chocolate dessert.
When it comes to dinner parties, birthday celebrations, or other special occasions, nothing beats a delicious and stunning layer cake. For more amazing layer cake flavors, try our berries and cream filled Chantilly Cake and Ultimate Carrot Cake with Carrot Jam.
Table of contents
Sabrina’s Chocolate Mousse Cake Recipe
This rich, three-layer Chocolate Mouse Cake is showstopping, decadent and delicious, but best of all it’s actually not that difficult to make. You do need to set aside a chunk of time for each element of the dessert: the cake, the mousse filling, and the frosting. There are no complicated techniques or specialized equipment required to make this the perfect cake, just a bit of patience and a whole lot of chocolate!
- Cocoa Powder: To give the recipe its rich, dark chocolate flavor, you’ll need 1 cup of unsweetened dark cocoa powder. If you prefer a lighter chocolate flavor, you can swap it out for regular unsweetened cocoa powder. You’ll also use dark cocoa powder to flavor the dark chocolate frosting.
- Hot Coffee: Adding freshly brewed coffee to your cake batter is a great way to enhance the chocolate flavor. The coffee acts as a liquid ingredient to soften the batter. It also enhances the chocolate flavor and makes the recipe sweeter.
- Dark Chocolate: Instead of using cocoa powder, you’ll use real dark chocolate to flavor the chocolate mousse. Melt the dark chocolate chunks into a smooth mixture that you can fold into the creamy mousse.
- Heavy Cream: Heavy whipping cream is a key component of the mousse. Be sure to use chilled cream, and whip the mixture until stiff peaks stand on their own.
- Eggs: You’ll use eggs both in the cake batter and in the chocolate mousse recipe. However, for the mousse filling, you need to remove the egg yolks. The egg whites create a light, airy mixture perfect for blending with the whipped cream. You’ll also add granulated sugar to the egg whites to sweeten the mousse base.
Kitchen Tools & Equipment
- Stand Mixer
- 9-inch Round Cake Pans
- Piping Bag
- Offset Spatula
- Mixing Bowls
How to Make
Time needed: 4 hours.
- Prep for Baking
Preheat your oven. Grease three 9-inch cake pans with butter and dust them with cocoa powder.
- Cake Batter
Add the sugar, flour, cocoa powder, baking powder, baking soda, and salt to your stand mixer. Turn the electric mixer to its lowest speed to sift the dry ingredients. Add the eggs, milk, oil, and vanilla to a separate bowl. Whisk the wet ingredients together then add to the stand mixer bowl, and turn on low speed. Slowly raise to medium speed until the wet and dry ingredients are just combined. Turn off the electric mixer. Carefully pour in hot coffee and stir it into the chocolate mixture by hand.
- Bake the Cakes
Divide the cake batter evenly into each of the prepared cake pans. Place them in the preheated oven and bake for 25-30 minutes. Remove the pans from the oven and let the cake layers cool completely before frosting.
- Make the Mousse
Beat the heavy whipping cream in a stand mixer on high speed for 2 minutes or until stiff peaks form. Transfer to a separate bowl and wipe the stand mixing bowl clean and dry. Beat the egg whites on high speed until soft peaks form. Add the granulated sugar and beat for another 20 seconds until stiff peaks form. Melt the chocolate in the microwave. Gently begin folding the melted chocolate into the egg whites. Once it’s mostly folded, add the whipped cream and continue folding the mixture until combined. Cover and refrigerate. Transfer to a piping bag to fill the cake.
- Make the Frosting
In a large saucepan, melt the butter over medium heat. Whisk in the unsweetened cocoa powder, and whisk until combined. Remove from heat and let it cool. Transfer the chocolate mixture to a stand mixer and beat on medium speed while adding the powdered sugar and milk alternately ⅓ cup at a time then add the vanilla.
- Prep for Assembly
Transfer the chilled mousse to a large piping bag and cut open the end of it so it’s about 3/4? wide. Spread a spoonful of the frosting to your cake plate. Level the cakes and brush off excess crumbs before adding the first cake layer to the plate.
- Assemble the Cake
Pipe half of the chocolate mousse evenly over the top of the cake layer. Use a rubber spatula to spread it evenly. Top with a second chocolate cake, then pipe another mousse layer on top. Add the third chocolate cake layer. Apply a thin layer of frosting to the outside of the cake. Refrigerate for 30 minutes to let the chocolate frosting harden.
- Decorate the Cake
Add a final layer of chocolate frosting over the outside of the entire cake. Pipe swirling mounds of chocolate frosting on top of the cake. Keep chilled until serving.
Can this be made ahead of time?
Absolutely and it’s actually better to prep your layer cake in advance because it means perfectly cooled layers, the mousse is set and you can just focus on assembling and decorating. You can make each layer a couple days ahead. Transfer the mousse and frosting to sealed containers and wrap the cake layers in plastic wrap.
Chocolate Mousse Cake Tips
- Freeze the Cake Layers
A seasoned baker hack is to prep the cake layers the night before and freeze them! Not only does this ensure your cakes are fully chilled, you’ll have way less crumbs when you go to frost them. Even out the cakes after they cool to room temperature, then wrap them in plastic and freeze. Assemble the cake while the layers are frozen and they will thaw by the time you serve the cake.
- Don’t Rush this Cake!
The key to making a layer cake is to allow plenty of time for cooling the cake layers so your frosting doesn’t melt off and your cake doesn’t crumble. Additionally, you want to make sure your mousse is chilled and set so it doesn’t melt. Realistically, this cake should take about 3-4 hours to prep the batter, bake the layers, cool the layers, make the filling and frosting, assemble, and decorate the cake.
How to Store
Store: Because of the mousse filling, you shouldn’t leave this chocolate cake recipe sitting at room temperature for more than a few hours. To keep the cake fresh, you can cover it in plastic wrap or put individual pieces in an airtight container to store in the fridge. It can keep well for up to 5 days.
Freeze: You can also freeze the assembled cake for up to 3 months. Double-wrap the cake in plastic wrap before freezing it to ensure it’s sealed. When you’re ready to serve the cake, transfer it to the fridge to thaw before enjoying it.
Ideas to Decorate Chocolate Mousse Cake
Toppings: Sprinkle decorations like grated chocolate, chopped nuts, and sprinkles over the swirled frosting mounds. Spread Chocolate Ganache or Salted Caramel Sauce over the top before piping the swirls, then drizzle more sauce on the frosting mounds.
Berries: Pile your favorite berries on the frosted cake, filling in the circle of frosting mounds. Add a whole or halved berry on top of each mound. You could also sprinkle fresh berries on the mousse filling of each layer too.
If the chocolate mousse mixture is turning out runny, it’s probably because the whipped cream wasn’t stiff enough or because you overmixed the chocolate mixture. To avoid this, be sure to whip together the cream mixture until it holds peaks. When you combine the chocolate with the cream, be careful not to overmix and break all the air pockets. The air pockets keep the mixture fluffy and help it to all set into the right texture.
Chocolate ganache is a simple chocolate glaze made with heavy cream and chocolate. On the other hand, fluffy mousse has more components, including egg whites, heavy cream, and melted chocolate. The airy mousse mixture makes the perfect filling for this dark chocolate cake recipe.
- 2 cups sugar
- 2 cups flour
- 1 cup unsweetened dark cocoa powder
- 1 1/2 teaspoons baking powder
- 1 1/2 teaspoons baking soda
- 1 teaspoon salt
- 2 large eggs
- 1 cup whole milk
- 1/2 cup vegetable oil
- 1 tablespoon vanilla extract
- 1 cup hot brewed coffee
- 1 cup dark chocolate chunks
- 2 cups heavy cream , very very cold
- 4 large egg whites
- 3 tablespoons sugar
Dark Chocolate Frosting:
- 3/4 cups unsalted butter
- 1/2 cup unsweetened dark cocoa powder
- 3 cups powdered sugar
- 1/3 cups whole milk
- 1 teaspoon vanilla extract
- Preheat the oven to 350 degrees and butter and dust with cocoa powder three 9″ cake pans.
- In a stand mixer on low speed mix together the sugar, flour, dark cocoa powder, baking powder, baking soda and salt.
- In a small bowl whisk together the eggs, milk, oil and vanilla then add it to the stand mixer on low then medium speed until just combined and finally add in the hot coffee carefully and stir it in by hand until just combined (do not turn on the mixer, it may splash on you).
- Pour one-third of the batter into each of the pans and bake for 25-30 minutes then remove, let cool completely and frost with the chocolate frosting.
- Add the heavy cream to a stand mixer on high speed for 2 minutes until it reaches stiff peaks.
- Remove from the stand mixer and set aside.
- Wipe out the bowl and dry with a paper towel.
- Add in the egg whites on high speed and beat to soft peaks, about 1 minute.
- Add in the sugar and continue to beat to stiff peaks, about 20 seconds.
- Add the chocolate to a microwave safe bowl and microwave in 30 second increments, stirring between each time until smooth.
- Add the chocolate to the egg whites and gently fold it into the eggs.
- When mostly folded in, add in the whipped heavy cream and fold it together until the chocolate is fully incorporated.
- Refrigerate, covered until ready to use.
- Add to a large piping bag and cut open the end of it about 3/4″ long of a cut, so a thick amount comes out.
Dark Chocolate Frosting:
- Melt the butter in a large saucepan and whisk in the dark cocoa powder then remove from the heat and let cool.
- Add the cooled chocolate mix to your stand mixer and whip on medium speed adding the powdered sugar and milk, alternating them ⅓ at a time and finally add the vanilla in last.
- If the frosting is too thick, add a bit more milk.
- To your cake stand add a spoonful of chocolate frosting.
- Level the cakes with a large serrated knife and discard the cake pieces.
- Brush off excess crumbs.
- Add the first layer of the cake to the cake stand.
- Pipe half of chocolate mousse, spread evenly.
- Top with second layer of chocolate cake.
- Pipe a thick layer of chocolate mousse, spread evenly.
- Top with the third layer of the chocolate cake.
- Apply a thin layer of chocolate frosting, coating the outside of the cake.
- Refrigerate for 30 minutes to allow to harden.
- Frost the cake with the remaining chocolate frosting.
- Pipe swirly mounds onto the top of the cake.
Berry Filling: For a fruity contrast to the rich chocolate spread Strawberry Jam, or other favorite fruit jam, in between the cake layers before adding the chocolate mousse filling.
White Chocolate: To make a white chocolate filling for this recipe, you can follow the same directions, use melted white chocolate chips instead of dark chocolate.