Are you ready for this decadent triple chocolate mousse cake? That's right, this impressive dessert is made with moist chocolate cake, whipped cream chocolate mousse, and an easy two-ingredient chocolate ganache. It takes some time to create, but the end result is so worth it!
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This delicious triple chocolate mousse cake is made with a moist & rich chocolate sponge cake on the bottom and a thick layer of airy chocolate mousse spread on top. Then creamy chocolate ganache is poured and smoothed on the top and sides of the whole cake.
Growing up in Germany, I loved trying every chocolate dessert I could get my hands on. This chocolate mousse cake is my recreation of those decadent chocolate desserts.
This cake was inspired by my other German chocolate cake recipes, including Black Forest Bundt cake, simple Black Forest sheet cake, marbled Marmorkuchen, elegant Yule log cake, and German mole cake.
I tested every component of this recipe multiple times. At first, I overwhipped the mousse and it became so hard that it would have needed a knife to cut it! And my first ganache was more of a thick sludge than anything else...
After so many recipe tests, I've created foolproof methods for you to get the perfect cake, mousse, and ganache on the first try! So be sure to follow the recipe carefully and read all my tips! 😉
What is a Chocolate Mousse Cake?
This is a chocolate chocolate chocolate cake! That’s right, triple chocolate!!
Chocolate Cake
I used nearly the exact same chocolate cake recipe I used to make my own homemade wedding cake so you know it’s a good one! I replaced the buttermilk with sour cream though, to give this cake a little more structure to support the mousse.
Chocolate Mousse
Instead of messing around with egg yolks, egg whites, or gelatin, this rich mousse is made with whipped cream, cocoa powder, and melted chocolate. It’s so stable that I’ve used a similar whipped cream to hold up a four layer Black Forest Cake!
Chocolate Ganache
Silky smooth chocolate ganache is made from just 2 ingredients. Poured over the assembled cake, it creates a glossy, smooth exterior coating. The ganache melts in your mouth, and it adds an extra punch of chocolate flavor in each bite!
Ingredients and Notes
- All purpose flour
- Granulated sugar
- Unsweetened cocoa powder - I recommend using unsweetened cocoa powder. Dutch processed cocoa powder is not as acidic, so it won’t react with the leavening agents the same way and your cake will have a different texture.
- Salt
- Baking powder and baking soda
- Eggs
- Vanilla extract
- Coffee - Use strong, freshly brewed hot black coffee to enhance the flavor of the chocolate, without actually adding a coffee flavor to the cake.
- Vegetable oil
- Baking chocolate - I recommend using pure chocolate baking bars, which can be found in grocery stores next to chocolate chips in the baking aisle. Baking bars have more cocoa butter which will create a smoother texture. And while you can substitute chocolate chips, those usually contain stabilizers to help them hold their shape during baking, so they won’t create as smooth of a texture.
- Sour cream
- Heavy cream - Use heavy cream or heavy whipping cream that has at least 35% fat for the mousse and ganache. And keep it cold in the fridge which will make it easier to whip for the mousse.
- Vanilla extract
- Confectioners' sugar - Or use powdered sugar, which is similar just without added cornstarch.
How to Make this Recipe
Below is the process to make this recipe. For the full step-by-step directions and ingredient quantities, scroll down to the recipe card at the bottom of this post.
1. Whisk the flour, granulated sugar, cocoa powder, salt, baking powder and baking soda. Set aside.
2. In another large mixing bowl, whisk together the two eggs, vanilla extract, vegetable oil, and sour cream.
3. Add the wet ingredients into the dry ingredients and mix.
5. Pour the chocolate cake batter in a greased 9-inch cake pan or springform pan.
7. Melt the chocolate in a microwave safe bowl on 20 second intervals, stirring after each time.
9. Mix in the vanilla extract, sifted confectioners' sugar, and cocoa powder.
11. Trim off the sides and the top of the cake. Flip the cooled cake upside down onto a cake stand or serving platter.
13. Chop the baking chocolate and place it in a large heat-proof bowl.
15. Remove the cream from the heat and pour it over the chopped chocolate.
17. Pour the cooled ganache over the top of the chilled mousse cake.
4. Add the hot coffee to the batter and whisk to combine.
6. Bake for 40 to 50 min at 350°F, until a toothpick comes out clean from the center.
8. In a large mixing bowl, beat the cold heavy cream for a few minutes, just until it starts to thicken.
10. Add the melted chocolate and use a silicone spatula to gently fold the chocolate into the mixture.
12. Spread the chocolate mousse on top of the cake in an even layer. Place the cake in the fridge for at least 1 hour.
14. In a small saucepan on medium heat, bring the heavy cream to a simmer.
16. Whisk it until it’s smooth and glossy. Set aside to cool for 15 minutes.
18. Serve your cake immediately, or chill uncovered until you’re ready to serve it.
Carissa's Kitchen Tip
I recommend baking your cake either in a springform pan or a 9-inch round cake pan with tall walls and a removable bottom.
This will make it a lot easier to remove your baked cake in from the pan once it's cooled.
Different Ways to Make Mousse
There are many different ways to make mousse, and they vary slightly in method and flavor.
- Traditional French Method - Egg yolks are whisked with sugar, then melted chocolate. Whipped cream is then folded in along with beaten egg whites sometimes.
- Whipped Cream-Based - Heavy cream is beaten until it forms whipped cream. Then melted chocolate or cocoa powder is folded in and chilled to set.
- Gelatin-Set - Similar to the traditional French method, egg yolks are whisked with sugar, then melted chocolate. Bloomed gelatin is then added into the mixture prior to the whipped cream, which makes the mousse more stable.
- Aquafaba - The juice from canned chickpeas is called aquafaba, and can be used in a variety of desserts to make them vegan, like macarons with vegan meringue. Aquafaba is whipped with sugar to form stiff peaks, then cocoa powder is folded in and the mixture is chilled to set.
I prefer the whipped-cream based method, which is one of the simplest.
Recipe Tips
- Room temperature ingredients: Set your eggs and sour cream on the counter for about 20 minutes to come to room temperature before mixing into the cake batter.
- Cold ingredients: Use heavy cream for the mousse cold, straight from the fridge. This will help it whip up better.
- Cooled Chocolate: For the mousse, make sure you allow your melted chocolate about 15 to 20 minutes to cool to room temperature before adding the whipped cream. Otherwise it could cause the whipped cream to seize and become thick and grainy.
- Folding: To fold ingredients, use a large silicone spatula. Scrape along the center of the bottom of the bowl towards you, continue up the side, and scoop the mixture over the top of itself. Rotate the bowl 90 degrees and continuing repeating these steps.
Variations
- Hot Coffee vs. Hot Water: The hot coffee enhances the chocolate flavor of the cake without adding a coffee flavor. So your cake will taste more intensely like chocolate, not like coffee. However, if you don’t want to add it, you can substitute hot water. The hot liquid helps "bloom" the cocoa, enhancing its chocolatey flavor.
- Layer Cake: You can also slice the cake in half widthwise to create two cakes. Then spread half the mousse in the middle and the other half on top of the stacked layers.
- Chocolate Chips: Fold dark chocolate chips, semi sweet chocolate chips, or even white chocolate chips into the cake batter for more chocolate flavor!
How to Make this Cake Ahead of Time
- Cake: You can bake the cake ahead of time, allow it to cool, then wrap it in plastic wrap and store at room temperature for up to 2 days, or in the freezer for up to 3 months.
- Mousse: You can make the mousse up to 2 days ahead of time and store it in the fridge.
Storage
- Room Temperature: You can keep the cake at room temperature while you're serving it, but I don't recommend storing it for more than a few hours at room temperature, since the mousse will start softening and melting.
- Fridge: Store leftover cake with plastic wrap covering the sides of any slices in the fridge for up to 1 week.
Related Recipes
Looking for more delicious cake recipes like this? Try these:
Triple Chocolate Mousse Cake
Equipment
- measuring cups and spoons
- mixing bowls
- Large Spoon or Spatula
- whisk
- small saucepan
Ingredients
Chocolate Cake
- 1¾ cups all purpose flour
- 1¾ cups granulated sugar
- ¾ cup unsweetened cocoa powder
- 1 teaspoon salt
- 1 teaspoon baking powder
- ½ teaspoon baking soda
- 2 large eggs
- 1 Tablespoon vanilla extract
- ½ cup vegetable oil
- ¾ cup sour cream
- ¾ cup strong, freshly brewed hot black coffee
Chocolate Mousse
- 8 ounces baking chocolate (see note below)
- 1 pint heavy cream (2 cups) cold, straight from the fridge
- 2 Tablespoons confectioners' sugar sifted (or powdered sugar)
- 3 Tablespoons unsweetened cocoa powder sifted
- 1 teaspoon vanilla extract
Chocolate Ganache
- 6 ounces baking chocolate (usually sold in 4 ounce bars in the baking aisle)
- 1 cup heavy cream (or heavy whipping cream)
Instructions
MAKE THE CAKE
- Preheat the oven to 350°F. Grease a 9-inch round cake pan with tall walls and a removable bottom or a springform pan.
- In a large mixing bowl, whisk together the all purpose flour, granulated sugar, unsweetened cocoa powder, salt, baking powder and baking soda. Set aside.
- In another large mixing bowl, whisk together the two eggs, vanilla extract, vegetable oil, and sour cream.
- Add the wet ingredients into the dry ingredients and mix it with a large spoon or spatula until there is no dry mixture visible. (It’ll be very thick and pretty dry at this point)
- Add the hot coffee (or substitute hot water) and whisk to combine. (It’ll be thick at first, but it’ll become smooth after a little mixing.)
- Pour the chocolate cake batter in the greased cake pan. Bake for 40 to 50 minutes, until a toothpick comes out clean from the center of the cake.
- Let the cake cool for 15 minutes, then remove it from the cake pan. Allow it to cool to room temperature for at least one hour on a cooling rack.
MAKE THE MOUSSE
- While the cake cools, make the mousse.Melt the chocolate: You can melt it in a microwave safe bowl on 20 second intervals, stirring well after each time. Or melt it with a double boiler on the stove. Set aside to cool to room temperature.
- In a large mixing bowl with a hand mixer or in the bowl of a stand mixer with the whisk attachment, beat the cold heavy cream for a few minutes, just until it starts to thicken.
- Add the vanilla extract and sift in both the confectioners' sugar and cocoa powder while mixing on a low speed. Continue to beat the mixture until it thickens and begins to form soft peaks. (Be careful not to over-mix the cream.)
- Add the melted chocolate and use a silicone spatula to gently fold the chocolate into the cream. Don’t mix too vigorously, otherwise the mousse will become thick and crumbly.
ASSEMBLE THE CAKE
- Trim off the sides and the top of the cake with a serrated knife to make it flat. Flip the cooled cake upside down onto a cake stand or serving platter. (This is a trick so the top of the cake is flat and doesn't have a mess of loose crumbs.)
- Spread the chocolate mousse on top of the cake in an even layer. Smooth the top and sides with an offset spatula or the back of a spoon.
- Place the cake in the freezer for about 20 minutes (or in the fridge for anywhere from 1 to 4 hours) while you prepare the ganache.
MAKE THE GANACHE
- Chop the chocolate into small pieces and place them in a large heat-proof bowl. Set aside.
- In a small saucepan on medium heat, bring the heavy cream to a simmer.
- Once the cream starts to bubble, remove it from the heat and pour it over the chopped chocolate. Let it sit, without stirring, for about 1 to 2 minutes until the chocolate softens and starts to melt.
- Whisk it until it’s smooth and glossy. Set aside to cool for 15 minutes.
DECORATE THE CAKE
- Remove the cake from the fridge or freezer.Pour the cooled ganache on top of the chilled mousse cake. Allow the ganache to run down the sides of the cake as well. You can smooth the sides with a bench scraper or offset spatula.
- Serve your cake immediately, or chill uncovered until you’re ready to serve it. Optional: Use a vegetable peeler and a bar of chocolate bar to decorate the top of the cake with chocolate curls.
Notes
- Room temperature ingredients: Set your eggs and sour cream on the counter for about 20 minutes to come to room temperature before mixing into the cake batter.
- Cold ingredients: Use heavy cream for the mousse cold, straight from the fridge. This will help it whip up better.
- Cooled Chocolate: For the mousse, make sure you allow your melted chocolate about 15 to 20 minutes to cool to room temperature before adding the whipped cream. Otherwise it could cause the whipped cream to seize and become thick and grainy.
- Folding: To fold ingredients, use a large silicone spatula. Scrape along the center of the bottom of the bowl towards you, continue up the side, and scoop the mixture over the top of itself. Rotate the bowl 90 degrees and continuing repeating these steps.
- Make Ahead: You can bake the cake ahead of time, allow it to cool, then wrap it in plastic wrap for up to 2 days ahead of time. You can make the mousse up to 2 days ahead of time and store it in the fridge.
- Storage: Store leftover cake with plastic wrap covering the sides of any slices in the fridge for up to 1 week.
shkalen
So much choooocooooo, i love it!
Bima
I made, I ate, I LOVE! so good
Carissa Erzen
Hahaha I'm so glad! Thanks!!