Hot Chocolate Marshmallow Mousse Cake
Two desserts in one! Rich and moist chocolate cake topped with the lightest, dreamiest milk chocolate marshmallow mousse.
This Chocolate Mousse Cake is super decadent and delicious! A rich one-bowl chocolate cake topped with milk chocolate marshmallow mousse. It’s fluffy, light, airy, and silky smooth. It’s got all the milky, chocolatey goodness and all the ingredients of a hot chocolate in a cake.
Two desserts in one
This cake is a mashup made in heaven; part moist chocolate cake and part melt-in-your-mouth chocolate mousse.
- Chocolate Cake: My go-to chocolate cake recipe. It’s rich and chocolatey, but still fluffy and light. It uses vegetable oil, buttermilk, and hot coffee to add moistness and enhance the chocolate flavour. Plus, it comes together in one bowl (or standmixer), making it super quick and easy to get baking.
- Chocolate Mousse: A light and airy chocolate mousse made with milk chocolate, mini-marshmallows, and whipped cream. It’s so incredibly smooth and velvety. It uses marshmallows as a thickening agent to help stabilize the mousse. However, it doesn’t taste of marshmallows, just milky chocolate cream.
How to make hot chocolate marshmallow mousse cake
Step 1: Preheat oven to 350°F. Grease an 8-inch square cake pan and line it with parchment paper.
Step 2: Make the cake batter. In the bowl of a stand mixer fitted with the paddle attachment, add the dry ingredients for the cake and stir to combine. Add the eggs, buttermilk, vegetable oil, and vanilla. Mix on low until combined. With the mixer on low speed, slowly stream in the hot coffee. Beat on medium speed until smooth, about 2 minutes. Pour the batter into the prepared cake pan.
Step 3: Bake for 25-30 minutes, until a toothpick inserted in the center comes out clean. Cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.
Step 4: While the cake cools, make the mousse. In a pot over low heat, melt together the mini-marshmallows, milk chocolate, and milk.
Step 5: Stir constantly, until melted and combined, about 5-7 minutes. Remove from the heat and cool completely.
Step 6: With a handheld mixer or stand mixer, beat the heavy cream and vanilla until soft peaks form.
Step 7: Fold the whipped cream into the cooled chocolate marshmallow mix.
Step 8: Spread the mousse over the cooled cake. Chill for 30 minutes, or until ready to serve.
Make it a chocolate mousse layer cake
Just a few extra steps turn this sheet cake into a layer cake!
- Double the ingredients, for both the cake and the mousse.
- Bake the cake layers. Bake the cake in three 6-inch round or two 8-inch round baking pans (greased and lined with parchment) at 350°F for 30-35 minutes, until a toothpick inserted in the center comes out clean.
- Chill the mousse. Once the mousse has cooled to room temperature, chill it in the refrigerator for 30 minutes, or until ready to use.
- Assemble. Place one layer of cake on a cake board, cake stand, or serving plate. Spread a layer of mousse evenly over top, getting right to the edges (use half the mousse for two cake layers, or one third for three cake layers). Gently place the second layer of cake on top. Spread another layer of mousse evenly over top. If using, repeat with the third layer of cake and final layer of mousse. Use a spatula or bench scraper to smooth the mousse around the edges of the cake, giving you a naked cake effect. Chill in the refrigerator for 30 minutes, or until ready to serve.
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Hot Chocolate Marshmallow Mousse Cake
Ingredients
- 1 cup all-purpose flour
- ⅔ cup granulated sugar
- ⅓ cup unsweetened natural cocoa powder
- 1 teaspoon baking soda
- ½ teaspoon baking powder
- ¼ teaspoon salt
- 1 egg
- ½ cup buttermilk
- ¼ cup vegetable oil
- 1 teaspoon pure vanilla extract
- ½ cup hot coffee, or hot water
For the mousse
- ¾ cup mini-marshmallows
- ½ cup milk chocolate chips
- ¼ cup whole milk
- 1 cup heavy cream
- ¼ teaspoon pure vanilla extract
Instructions
- Preheat oven to 350°F. Grease an 8-inch square cake pan and line it with parchment paper.
- In the bowl of a stand mixer fitted with the paddle attachment, add the dry ingredients for the cake and stir to combine.
- Add the eggs, buttermilk, vegetable oil, and vanilla. Mix on low until combined.
- With the mixer on low speed, slowly stream in the hot coffee. Beat on medium speed until smooth, about 2 minutes.
- Pour the batter into the prepared cake pan.
- Bake for 25-30 minutes, until a toothpick inserted in the center comes out clean.
- Cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.
For the mousse
- In a pot over low heat, melt together the mini-marshmallows, milk chocolate, and milk. Stir constantly, until melted and combined, about 5-7 minutes. Remove from the heat and cool completely.
- With a handheld mixer or stand mixer, beat the heavy cream and vanilla until soft peaks form.
- Fold the whipped cream into the cooled chocolate marshmallow mix.
- Spread over the cooled cake. Chill for 30 minutes, or until ready to serve.
Notes
Mousse recipe adapted from I Heart Eating.
