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This amazing Chocolate Mousse Cake recipe combines moist chocolate cake layers with a rich chocolate mousse filling and a warm chocolate frosting poured on top. It’s the ultimate chocolate lover’s cake!
Chocolate Mousse Cake is the most magical chocolate cake!
I love this Chocolate Mousse Cake because it’s the perfect balance of elegance and ease. The chocolate mousse couldn’t be simpler to make, and I often prep everything ahead of time so the final assembly is quick and stress-free. It’s a beautiful, impressive dessert that’s sure to wow any crowd, especially the chocolate lovers in your life! Best of all, the combination of moist chocolate cake with creamy mousse filling is absolutely divine. It’s rich without being too heavy, and always a crowd favorite.
Try my other cake recipes, like Chocolate Cobbler, Carrot Cake, Flourless Chocolate Cake, or Dulce de Leche Cake!
How to make Chocolate Mousse Cake:
Bake Chocolate Cake: Mix sugar, flour, cocoa powder, baking powder, baking soda, and salt in a large bowl. Add eggs, milk, oil, and vanilla. Beat with a hand mixer on medium speed for 2 minutes, stir in boiling water and prepare into prepared pans. Bake at 350°F for 30–35 minutes. (A box cake mix can be used if you prefer).
Make Chocolate Mousse: Mix cocoa powder and hot water until smooth. Melt chocolate chips in the microwave or use a double boiler. Add cocoa powder mixture to the melted chocolate and stir until smooth. Let cool to room temperature. Whip the cream and sugar together in a large mixing bowl until very stiff peaks. Add cooled melted chocolate and gently fold the mixture together to combine. Refrigerate until you assemble the cake.
Assemble the Cake: Once cakes are cool, slice each in half horizontally with a sharp serrated knife to create four layers. Place one of the cake rounds on the serving tray then spread a thin layer of chocolate mousse over it. Top with the next cake layer then repeat with the chocolate mousse between all layers. Smooth any extra chocolate mousse over the outside of the whole cake as a “crumb” coat. Refrigerate cake for at least 30 minutes, or up to 1-2 days if it's covered well.
Make Frosting & Serve: Heat milk, cocoa, and butter in a medium saucepan. Bring to a boil then remove from heat and beat in powdered sugar with electric mixers to get rid of any lumps. Cool for 15-20 minutes, until pourable but not too warm that it melts the mousse. Pour and smooth over chilled cake. I like to use pieces of parchment papers gently under the edges of the cake to catch the frosting as it drips down. I usually pour it slowly and catch it as it comes down the sides and smooth it along the sides. Serve chocolate mousse cake once set.
Layered Chocolate Mousse Cake Recipe
Equipment
Ingredients
Chocolate Cake:
- 2 cups granulated sugar
- 1 3/4 cups + 2 Tbsp all-purpose flour
- 3/4 cup unsweetened cocoa powder
- 1 1/2 teaspoons baking powder
- 1 1/2 teaspoons baking soda
- 1 teaspoon salt
- 2 large eggs
- 1 cup buttermilk
- 1/2 cup oil, (vegetable or canola oil)
- 2 teaspoons vanilla extract
- 1 cup boiling water, , or hot coffee
Chocolate Mousse:
- 1/2 cup hot water
- 4 Tablespoons unsweetened cocoa powder
- 1 1/2 cups semi-sweet chocolate chips
- 2 cups heavy whipping cream
- 2 Tablespoons granulated sugar
Chocolate Frosting:
- 6 Tablespoons milk
- 3 Tablespoons unsweetened cocoa powder
- 1/2 cup butter, (one stick)
- 3 3/4 cups powdered sugar
Instructions
Chocolate Cake:
- Heat oven to 350°F. Grease and flour two 8 or 9 inch round baking pans. (I like to line the bottom of mine with wax or parchment paper).
- Dry ingredients: Stir together sugar, flour, cocoa powder, baking powder, baking soda and salt in large bowl.2 cups granulated sugar, 1 ¾ cups + 2 Tbsp all-purpose flour, ¾ cup unsweetened cocoa powder, 1 ½ teaspoons baking powder, 1 ½ teaspoons baking soda, 1 teaspoon salt
- Add Wet Ingredients: Add eggs, buttermilk, oil and vanilla; beat on medium speed of mixer 2 minutes. Stir in boiling water (the batter will be thin). Pour batter into prepared pans.2 large eggs, 1 cup buttermilk, ½ cup oil, 2 teaspoons vanilla extract, 1 cup boiling water
- Bake for about 30 to 35 minutes or until a toothpick inserted in the center comes out clean. Allow cake to cool in the pan for 5 minutes and then remove to wire cooling racks. Cool completely. (You could freeze the cake rounds at this point, if desired.)
Chocolate Mousse:
- Stir the cocoa powder and hot water together. In a double-boiler (or in the microwave) melt the chocolate chips, just until smooth. Add the cocoa mixture to the melted chocolate chips and stir well to combine. Allow to cool to room temperature.½ cup hot water, 4 Tablespoons unsweetened cocoa powder, 1 ½ cups semi-sweet chocolate chips
- In a separate large bowl, beat the cream and sugar until very stiff peaks form. Add the chocolate mixture and fold in with a spatula until well combined. Refrigerate until ready to use, up to 5 days.2 cups heavy whipping cream, 2 Tablespoons granulated sugar
Chocolate frosting:
- In a medium saucepan, add milk, cocoa, and butter. Bring to a boil. Remove from heat. Add powdered sugar and mix with electric beaters to get rid of any lumps. Allow to cool for 15-20 minutes, stirring occasionally.6 Tablespoons milk, 3 Tablespoons unsweetened cocoa powder, ½ cup butter, 3 ¾ cups powdered sugar
- Torte Cakes: Once cakes have cooled, use a sharp serrated knife to torte each cake (cut each cake evenly in half, horizontally, so that you end up with four, thin, 9'' cake pieces).
- Layer mousse: Place one cake layer on a serving plate. Spread a big spoonful of mousse on top of that cake layer. Repeat with the remaining cake layers, adding a layer of mousse filling between each layer of cake. Use remaining mousse filling to spread it evenly around the entire outside and top of the cake. Refrigerate for 30 minutes.
- Chocolate Frosting: (I usually make the warm chocolate frosting while the cake is in the fridge.) Remove cake from fridge and very slowly pour the cooled chocolate frosting over the top. Use a spatula or knife to gently spread the frosting evenly over the outside of the cake as you pour. Refrigerate until ready to serve.
Notes
- Mousse: Place in an airtight container in the fridge for up to 5 days. Fold it again gently with a spatula before using. But the texture is best the day of.
- Cake Rounds: These can be made in advance and frozen. Once baked, cool them completely and then wrap them in a double layer of plastic wrap. Place in a freezer safe bag and freeze for up to 3 months.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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*I first shared this recipe in May 2014. Updated May 2018, February 2022 and October 2025.
Can you use buttercream icing on cake instead?
Yes, sure!
Just made the cake and have lots of mousse filling left over – any ideas how I can use it up or if I can freeze it for when I make the cake again? Thanks!!
I made the cake the other day and everything worked out perfectly. The cake was nice and moist, and came out of my Pam’s no problem, I only used grease and flour.
I went to make another one more recently and I opened the oven to find that my batter had gone over the edges and the center didn’t seem done still. Anyone have any suggestions or insights?
I’ve made the Hershey’s chocolate cake several times and love it. Made it tonight with buttermilk instead of milk and it turned out weird… It was dense add chewy… Not great. I don’t recommend using buttermilk here!
The rest of the parts were great!
Very disappointed. Made the cake and followed instructions. Cakes looked fine when came out the oven. They looked OK when I cut them in half. But once I stocked them on top of each other with the mousse in the middle, the cakes started to crumble badly and completely broke off into a huge mess. I put a lot of effort into this. My friend bought the ingredients for me because I’m avoiding going to the store during the Coronavirus. My daughter asked for this cake for her birthday and now I don’t have a cake for her and will have to bake something very basic for her birthday with whatever ingredients are left in my pantry. I buttered the pans and floured them. The cake didn’t stick and seemed fine. The problem was that the cake crumbled and big parts of it broke off after laying it. Big mess. I had to toss it all out. If you are considering baking this cake, consider again. I wish I read the reviews before deciding to make this.
Made cake and mousse last night and refrigerated. Making frosting in a bit and then assembling. Question— do I leave mousse get to room temp first before spreading?
Thanks. Can’t wait to try a piece!
You don’t need to let the mouse come to room temperature. Enjoy!
I Used parchment paper and then sprayed it with Bakers Joy and did not have any trouble at all with the cake coming out… It was absolutely delicious and a big hit. It will become one of my favorite go-to desserts.
I also had trouble with my cake layers sticking to the pan. I threw away the first cake. I’ll make it again with the mousse filling and frosting. But I will use a more reliable recipe for the cake itself.
Line your pans with parchment paper and then spray them lightly with cooking spray.
I made this for my husband’s birthday this past weekend and I could NOT believe how DELLLLICIOUS and MOIST it was! Its incredible. I made the cake Friday, used parchment and spray with no issues. I tasted tiny bits that fell off and was a bit disappointed…just kinda tasted normal, nothing special. I let it sit in the fridge until Saturday evening when I put it all together and WOW! The cake part was incredible, the mousse was my husband’s favorite part, and the frosting my daughter’s fav. Will FOR SURE make this again! THANK YOU!
I have made this cake recipe for years, and it has always come out perfectly. Do you live at a higher elevation where adjustments need to be made? I use Crisco to grease pan, add waxed paper circle (and grease it), then flour the whole pan.
I made the mousse filling for a smash cake. It was delicious. Don’t skimp on the sugar. I did at first since it’s for a baby. And the chocolate was too bitter. Added the sugar and it balance it right out.
Thanks for sharing!
I was so excited to make this cake. Prepared pans exactly how in recipe, but when I tried to remove cake from pan the cake broke in half and fell completely apart. I’ve never had a cake do that before. So crumbly that it doesn’t seem to want to stay together. It’s weird because its seems moist at the same time. Not sure what happened, very disappointed.
If you try to turn a cake out straight away it will break. Leave it in the tin to cool for 5 to 10 minutes before turning it out
What kind of milk should be used for the cake and frosting? Whole milk? Thanks it looks delicious!
I would NOT use skim milk, but any other kind will work. Whole milk or 2% would be delicious.