My triple chocolate mousse cake is ridiculously decadent. I layered devil’s food cake, fluffy chocolate mousse, and creamy chocolate ganache to create this indulgent dessert. It’s stunning to look at and deceptively simple to make– the perfect dessert for a fancy dinner party or a romantic Valentine’s Day feast.
Triple Chocolate Mousse Cake
This chocolate mousse cake is super easy to make but involves a lot of waiting around for things to chill and set. I promise it’s worth the wait, though! The chocolate mousse is so light and fluffy, and the ganache is rich and creamy. I shaved off a little prep time by using boxed cake mix, and it really helped make this recipe fly by.
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How to Store
In an airtight container in the fridge, chocolate mousse cake will stay fresh for up to 5 days. I like to serve it slightly chilled.
Tips for Success
- I used Betty Crocker devil’s food cake, but any kind of chocolate cake will work.
- If you’re looking for a homemade cake, try my devil’s food cake recipe!
- If you only have gelatin leaves on hand, you can use 2 leaves of gelatin in place of the 2 teaspoons of powdered gelatin.
- If your mousse turns out a bit runny, it’s probably because the whipped cream was not stiff enough before you incorporated the chocolate and gelatin mixture. Avoid this issue by whipping the cream until stiff peaks form.
- Your mousse needs time overnight to sit before the ganache is poured on top. Do not try to rush this process!
Chocolate Mousse Cake Recipe
Ingredients
For the Cake
- 7.625 ounces Devil's food cake mix (½ of a 15.25-ounce box)
- ⅝ cup water
- ¼ cup vegetable oil
- 1 large egg
- 1 large egg yolk
For the Chocolate Mousse
- 2 teaspoons powdered plain gelatin
- 2½ tablespoons cold water
- 2¼ cups chocolate chips
- 3 cups heavy cream divided
- ½ cup powdered sugar
For the Ganache
- 8 ounces chocolate chips
- ⅔ cup heavy cream
- Chocolate shavings optional, for garnish
- Fresh berries optional, for garnish
Equipment
- Kitchen Scale (optional)
- 9-inch Springform Pan
- Stand Mixer (optional)
- Hand Mixer (optional)
Instructions
For the Cake
- Prepare ½ package of cake mix according to the instructions on the box with water, vegetable oil, and eggs. Bake in a 9-inch springform pan according to the instructions (around 25 minutes) and let cool on a wire rack while you prepare the mousse.7.625 ounces Devil's food cake mix, ⅝ cup water, ¼ cup vegetable oil, 1 large egg, 1 large egg yolk
For the Chocolate Mousse
- In a small bowl, combine the gelatin and cold water and bloom for 5-10 minutes.2 teaspoons powdered plain gelatin, 2½ tablespoons cold water
- Meanwhile, place chocolate chips in a heatproof bowl. In a small saucepan set over medium-high heat, bring 1 cup of heavy cream to a simmer (between 112-115°F), then remove from the heat.2¼ cups chocolate chips, 3 cups heavy cream
- Whisk in the bloomed gelatin and stir until completely dissolved. Pour mixture over the chocolate chips and whisk until melted and combined. Allow mixture to cool, stirring occasionally.
- In the bowl of a stand mixer fitted with the whisk attachment, or with a hand mixer in a large bowl, beat the remaining 2 cups of cream with the powdered sugar until stiff peaks form.½ cup powdered sugar
- Stir about ¼ cup of the whipped cream into the melted chocolate. Gently fold in the remaining whipped cream until fully incorporated.
- Spread the chocolate mousse evenly on top of the cooled cake while still inside the pan.
- Cover with plastic wrap and refrigerate for at least 8 hours or up to overnight.
For the Ganache
- Once the cake has chilled overnight, place the chocolate chips in a heatproof bowl. In a small saucepan set over medium-high heat, bring ⅔ cup of heavy cream to a simmer (between 112-115°F), then remove from the heat.⅔ cup heavy cream, 8 ounces chocolate chips
- Pour the warm cream over chocolate chips and allow to sit for 3-4 minutes, then whisk gently until smooth and shiny. Allow to cool until slightly thickened, then pour over the mousse.
- Cover and chill for 1 hour. Serve garnished with chocolate shavings and berries, if desired.Chocolate shavings, Fresh berries
Notes
- Nutritional information does not include optional ingredients.
How to Make Chocolate Mousse Cake Step-by-Step
Bake the Cake: Prepare 7.625 ounces (½ box) of chocolate cake mix according to the instructions on the box using ⅝ cup water, ¼ cup vegetable oil, 1 large egg, and 1 large egg yolk. Bake in a 9-inch springform pan according to the instructions (around 25 minutes) and let cool on a wire rack while you prepare the mousse.
Bloom the Gelatin: In a small bowl, combine the 2 teaspoons of powdered plain gelatin and 2½ tablespoons of cold water and bloom for 5-10 minutes.
Melt the Chocolate: Meanwhile, place 2¼ cups of chocolate chips in a heatproof bowl. In a small saucepan set over medium-high heat, bring 1 cup of heavy cream to a simmer (between 112-115°F), then remove from the heat. Whisk in the bloomed gelatin and stir until completely dissolved. Pour mixture over the chocolate chips and whisk until melted and combined. Allow mixture to cool, stirring occasionally.
Whip the Cream: In the bowl of a stand mixer fitted with the whisk attachment, or with a hand mixer in a large bowl, beat the remaining 2 cups of cream with ½ cup of powdered sugar until stiff peaks form.
Mix the Mousse: Stir about ¼ cup of the whipped cream into the melted chocolate. Gently fold in the remaining whipped cream until fully incorporated.
Chill the Mousse: Spread the chocolate mousse evenly on top of the cooled cake while still inside the pan. Cover with plastic wrap and refrigerate for at least 8 hours or up to overnight.
Make the Ganache: Once the cake has chilled overnight, place 8 ounces of chocolate chips in a heatproof bowl. In a small saucepan set over medium-high heat, bring ⅔ cup of heavy cream to a simmer (between 112-115°F), then remove from the heat. Pour the warm cream over chocolate chips and allow to sit for 3-4 minutes, then whisk gently until smooth and shiny. Allow to cool until slightly thickened, then pour over the mousse.
Set the Ganache: Cover and chill for 1 hour. Serve garnished with chocolate shavings and berries, if desired.
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