Moist chocolate cake layered with rich chocolate mousse and topped with creamy chocolate buttercream. The perfect chocolate cake.
My Wedding Cake
My husband and I are big chocolate lovers. I made our wedding cake (shown below) and, of course, it was a chocolate cake with chocolate mousse filling and chocolate buttercream. It tasted amazing, but it did not look too good. The sides were not straight and the buttercream started to crack, so we had to cover it with ribbon when we got to the reception center. It was pretty funny and we got a good laugh.
I’ve learned a lot in the 3 ½ years I have been married and I knew I wanted to recreate our wedding cake, but with recipes I created.
With my 40th birthday this month felt like the appropriate time to give it a go and I did it! The cake is moist and delicious and the chocolate mousse I can eat by the spoonfuls. The chocolate buttercream is rich and smooth. I can still work on my frosting skills, but I am so happy with how it turned out.
I love the feeling I get when I create a recipe on my own and this one is good!
Below, I break down all the steps, so you can make this moist and delicious cake too.
Why You’ll Love This Recipe
- Moist, delicious cake layers
- Rich chocolate mousse you can eat by the spoonfuls
- Easy chocolate buttercream you can use for any cake or cookies
How to Make Chocolate Mousse Cake
1. CAKE BATTER:
In a large mixing bowl, mix flour, sugar, cocoa, salt, baking soda, baking powder. In a separate mixing bowl, mix buttermilk, sour cream, eggs, oil, and hot water. Make sure to use room temperature ingredients, so the wet ingredients mix well in the batter.
2. BAKE:
Using a kitchen scale, divide batter between three 8 inch round cake pans, greased with parchment paper. About 24 ounces of cake batter will be in each cake pan. Bake at 325° F (160° C) for 20-25 minutes. Allow cakes to cool for about 15 minutes, remove from cake pan and allow to cool completely on a cooling rack.
3. CHOCOLATE MOUSSE:
Chill a metal mixing bowl and whisk attachment (for hand mixer), for ten minutes. While the bowl is chilling, make chocolate ganache by heating heavy whipping cream in the microwave for 45 seconds. Pour hot cream over chocolate chips and stir until it’s smooth. Set it aside and allow it to cool. In a small bowl, add cold water and sprinkle gelatin on top and let it sit for one minute. Pour boiling water (I heat it in the microwave for one minute) over gelatin and stir until gelatin is dissolved and set aside. In the chilled bowl, add remaining heavy cream and beat with a hand mixer until stiff peaks form. Add powdered sugar and vanilla and beat until well combined. Add gelatin and beat until well combined. Using a silicone spatula, fold in chocolate ganache until well combined. Make sure to mix until no white streaks are showing. Chill mousse in the refrigerator for at least two hours.
4. CHOCOLATE BUTTERCREAM:
In a stand mixer with the paddle attachment, beat butter for about five minutes. Add powdered sugar and beat until smooth. Slowly add cocoa powder and mix until smooth. With the mixer on low, add heavy whipping cream and salt. Beat on medium speed until smooth and no air pockets are visible. About 5-10 minutes.
5. ASSEMBLE:
Place one cake layer on a cake board, bottom side down. Pipe a rim about the top edge of the cake layer to create a barrier for the filling. Spread half of the chocolate mousse on the cake layer. Taste the mousse, it’s important to sneak a bite or two for the cake to come out perfect. 🙂 Place the second cake layer on top of the mousse layer with the bottom side up and repeat as stated before. Place the last cake layer, bottom side up. Frost cake with buttercream using a cake spatula, or butter knife. You can use a cake scraper to smooth the frosting or use the back of a spoon for a beautiful rustic look.
Tips for the Best Cake
- Use room temperature wet ingredients
- Break up making cake over a few days
- Day 1: Make cake layers
- Day 2: Make chocolate mousse and buttercream
- Day 3: Assemble cake
- Oven temperatures vary, so watch cake closely to not overbake
Helpful Tools
- Round Cake Pans: I love these 8” round cake pans and these 6” round cake pans.
- Stand mixer with paddle attachment: I love my KitchenAid mixer and my Kitchen Aid hand mixer.
- Liquid measuring cups: These Pyrex liquid measuring cups are great.
- Measuring cups and spoons: I use this set of measuring cups and spoons.
- Kitchen scale: This kitchen scale has great reviews and is similar to the one I use.
- Silicone spatula: I’m still looking for one that I love, so if you have one you love let me know in the comments.
- Cake turn table: I use this cake turntable and it is great. It also comes with an offset spatula, cake scraper, and piping tips.
- Cake boards: One 8 inch cake board and one 10 inch cake board would be helpful.
- You can assemble your cake directly on a cake stand or plate. If so, place strips of parchment paper or wax paper under the edges of your cake to collect frosting and remove once frosted.
More Chocolate Recipes You’ll Love
- Easy Mississippi Mud Cake Recipe
- The Best Double Chocolate Chip Cookies
- Copycat Cheesecake Factory Godiva Cheesecake
- The Best Ever Homemade Brownie Recipe
Final Thoughts
This Chocolate Mousse Cake will always hold a special place in my heart for many reasons. I hope you love it as much as I do. If you try it, I’d love to hear what you think! Leave a comment below or tag me @sweetbitesbylaurel, so I can see what you’re baking.
Moist and Delicious Chocolate Mousse Cake
Equipment
- Round Cake Pans
- Stand mixer with paddle attachment
- Liquid measuring cups
- Measuring cups and spoons
- Kitchen scale
- Silicone spatula
- Cake turn table
- Cake boards
Ingredients
Chocolate Cake
- 1 ¾ cups (210 g) all-purpose flour
- ¾ cup (60 g) dutch processed cocoa powder
- 1 ½ cups (288 g) granulated sugar
- 1 teaspoon salt
- 1 ½ teaspoon baking soda
- 1 cup (240 g) buttermilk, room temperature
- 4 eggs, room temperature
- ½ cup (240 g) sour cream, room temperature
- 1 teaspoon vanilla
- ½ cup (112 g) vegetable oil
- ½ cup (113 g) hot water
Chocolate Mousse
- ⅓ cup (74 g) dark chocolate chips
- 1 ¼ cup (300 g) cold heavy whipping cream, divided
- 1 teaspoon gelatin
- 1 tablespoon cold water
- 2 tablespoons boiling water
- ¼ cup (30 g) powdered sugar, measured then sifted
- ½ teaspoon vanilla extract
Chocolate Buttercream
- 2 cups (454 g) unsalted butter
- 5 cups (600 g) powdered sugar, measured then sifted
- ½ cup (40 g) cocoa powder
- ¼ cup (60 g) heavy whipping cream
- ⅛ teaspoon salt
- 1 teaspoon vanilla
Instructions
Chocolate Cake
- Preheat oven to 325° F (160° C). Spray three 8 inch cake pans with nonstick cooking spray. Place parchment round on bottom of pans and spray with nonstick cooking spray again and set aside.
- In a bowl of a stand mixer or large mixing bowl, add all-purpose flour, cocoa powder, sugar, salt, and baking soda. Mix until just combined.
- In a mixing bowl, mix buttermilk, sour cream, eggs, vanilla, vegetable oil, and hot water.
- With the mixer on low speed, add wet ingredients to the dry ingredients. Mix until combined. Scrape sides and bottom of bowl and mix until combined.
- Pour batter into prepared cake pans evenly; about 24 ounces of batter in each pan.
- Bake cake for 20-25 minutes. Cake is done when the center no longer giggles and there are a few moist crumbs on a toothpick.
- Remove cakes from oven and allow to cool in pans for about 15 minutes. Remove cakes from pans and place on cooling rack to cool completely.
Chocolate Mousse
- Place metal bowl and whisk attachment in freezer for 10 minutes.
- In a small bowl, add chocolate chips. Set aside.
- Heat ¼ cup heavy whipping cream for 30 seconds in microwave. Pour hot cream over chocolate chips. Stir until smooth. Set aside and cool.
- Sprinkle gelatin over cold water in small bowl. Let sit for 1 minute. Add boiling water and stir until gelatin is completely dissolved. Cool slightly.
- In chilled metal bowl, beat remaining 1 cup heavy whipping cream until stiff peaks form. Add powdered sugar and vanilla; mix until combined. Pour in gelatin mixture and beat until well blended.
- Fold in chocolate ganache until well blended.
- Spread over cooled cheesecake and refrigerate for two hours. If cheesecake is not cooled, refrigerate until cake has cooled.
Chocolate Buttercream
- In a stand mixer with a paddle attachment, beat butter for about five minutes.
- Add sifted powdered sugar and mix until combined.
- With the mixer on low speed, add cocoa powder and mix until combined.
- Add heavy whipping cream, salt, and vanilla and mix on medium speed for another 5-10 minutes until smooth.
Assemble
- On a cake board or cake stand, place one layer of cake bottom side down. Pipe a rim of buttercream around the cake. You can use a ziploc bag and cut one corner to pipe a rim around the cake.
- Evenly spread half of the chocolate mousse on the cake layer. Top with another cake layer, bottom side up and repeat.
- Place last cake layer on top with bottom side up. Frost cake using a cake spatula or a butter knife. Smooth buttercream with cake scrapper or use the back of a spoon for a rustic look.
- Refrigerate cake for an hour, then wrap in plastic wrap until an hour before ready to serve. Remove cake from refrigerator 30 minutes to an hour before serving.
