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!

This easy Chocolate Mousse cake has layers of moist chocolate cake and a creamy homemade chocolate mousse, topped with a smooth chocolate frosting. It's elegant, delicious, and perfect for any occasion!

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.

Four process photos for how to make a chocolate mousse cake.

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Recipe

This easy Chocolate Mousse cake has layers of moist chocolate cake and a creamy homemade chocolate mousse, topped with a smooth chocolate frosting. It's elegant, delicious, and perfect for any occasion!
Prep 40 minutes
Cook 40 minutes
Cool time 45 minutes
Total 2 hours 5 minutes
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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

Chocolate cake recipe is our Hershey's Chocolate cake
Make Ahead Instructions:
  • 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

Calories: 640kcalCarbohydrates: 97gProtein: 8gFat: 27gSaturated Fat: 12gPolyunsaturated Fat: 3gMonounsaturated Fat: 10gTrans Fat: 0.3gCholesterol: 56mgSodium: 410mgPotassium: 321mgFiber: 5gSugar: 67gVitamin A: 385IUVitamin C: 0.3mgCalcium: 115mgIron: 4mg

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*I first shared this recipe in May 2014. Updated May 2018, February 2022 and October 2025.

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About The Author

Lauren Allen

Welcome! I’m Lauren, a mom of four and lover of good food. Here you’ll find easy recipes and weeknight meal ideas made with real ingredients, with step-by-step photos and videos.

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4.88 from 484 votes (357 ratings without comment)
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Sham
6 years ago

Hi, Lauren! What would it be like if I were to make this cake with white chocolate mousse instead?

Laura Curley
6 years ago

5 stars
Very moist n rich.

Lisa H
6 years ago

5 stars
Loved this recipe! So delicious. Mousse so, so good! I was pressed for time so I used boxed cake but next time I’ll try this cake recipe. I got so many compliments on how good the cake tasted. It was a big hit. My favorite was the mousse. It was so good! Since I was in a rush I kind of messed up putting the warm icing on the cold mousse covered cake. The recipe warned that this could happen so totally my fault. It didn’t look as pretty because of this but it tasted so good. Definitely a keeper and will make again when I have more time.

Elon Hawkins
6 years ago

4 stars
The cake looks delicious! Cake with chocolate frosting has been and always will be my favorite kind of cake. Where did you get the recipe from?

Pam
6 years ago

5 stars
I made this for my nephew in laws 40th birthday. I followed the directions as written except I used a 1/2 sheet pan, each layer was 2 recipes. I baked each layer around 50 to 55 minutes at 325 degrees. I tripled the mousse recipe to make sure I had a nice thick layer. I did use my old stand by ganache recipe for the frosting. It was a huge hit with everyone! Thanks for the recipe. I now have a special request to bring this cake to Thanksgiving but not as big.

Audrey Tomblin
7 years ago

I really want to try your recipe. Do you think if I do the recipe 1.5 x, it will make 2, 12 in round cake pans?

Mary
7 years ago

2 stars
I made this cake for my son’s birthday, and was disappointed. It was much too sweet! I think it was the frosting. But the mousse was tasty.

Brenda
7 years ago

5 stars
Made this for my husband’s birthday as he loves chocolate cake and this was his response, “this is the best cake I have ever had. Ever!” 🙂 It was delicious and have no doubt I will be making again.

Patience Renzulli
7 years ago

5 stars
This was my first ever cake from scratch and it turned out spectacularly!!!! Thank you so much! Not too sweet, plenty rich and chocolatey, without being cloying – just right! Thank you for this confidence builder and a delicious, special, and impressive dessert, of which a beginner was able to be proud.

Danielle
7 years ago

I just wanted to thank you for this awesome recipe! My dad said he wanted a “mousse cake” for his birthday and this was the perfect blend of mousse and cake! This recipe was super fun to make, and as a teen inexperienced with baking, i found it was super easy. The only changes I made were I replaced half a cup of the semisweet chocolate with unsweetened, and it gave it a wonderful richer and darker less sugary flavour which my dad loves! I did have quite a thick layer of mousse left over so I only dripped a small amount of chocolate ganache on the sides for a drippy effect and topped with whipped cream. My cake came out quite dense and filling, but other than that everything was great! Thank you for this wonderfully simple recipe!

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