Chocolate Mousse Cake

Rich and velvety Chocolate Mousse Cake is an impressive yet oh-so-easy cake recipe that’s sure to wow at the dessert table! It’s a triple threat made from layers of moist chocolate cake, fluffy chocolate mousse, and chocolate ganache, topped with chocolate whipped cream. 

Do you love chocolate mousse? Try my other recipes for No-Bake Chocolate Oreo Mousse Cake and Triple Chocolate Brownie Mousse Cake, too!

Smooth and Decadent Chocolate Mousse Cake

I finally combined my best-ever Chocolate Cake with my all-time favorite chocolate mousse recipe, and can I just say: Fireworks!

This easy chocolate mousse cake layers moist chocolate cake with velvety chocolate mousse, that’s then covered with a rich homemade chocolate ganache. But why stop there? I go all out and top this cake with chocolate whipped cream. Bring on ALL the chocolate.

When approaching this recipe, just take it layer by layer. It’s easy to make from start to finish, and it always impresses!

Key Ingredients

Aside from your usual baking staples (flour, sugar, baking powder, etc.), there are a few ingredients that set this mousse cake apart from other chocolate cakes. Below I’ve summarized the key ingredients, and don’t forget to refer to the recipe card for the full details at the bottom of this post.

For the Cake Layer 

• Oil – Using vegetable oil in place of butter in cake recipes is key to a moist and tender cake crumb.
• Sour Cream – My second secret for ultra-moist chocolate cake. If you don’t have sour cream, use plain Greek yogurt instead.
• Cocoa Powder – You’ll need cocoa powder for the cake as well as the chocolate mousse and whipped topping. You can use regular unsweetened cocoa powder, I use Hershey’s Special Dark.
• Coffee – You won’t taste the brewed coffee added to this cake, but it does wonders to enhance the chocolate flavors! If you’d prefer to go without it, use equal parts milk.

For the Chocolate Mousse Layer and Topping

• Gelatin – I bloom powdered gelatin in cold water before adding it to the base of the chocolate mousse. Gelatin helps to stabilize the mousse filling so that it’s smooth and creamy.
• Heavy Cream – You’ll use heavy whipping cream in the mousse, in the ganache, and again when making the whipped topping.
• Chocolate – I recommend using a high-quality dark chocolate bar like Ghirardelli in both the mousse as well as the ganache, rather than chocolate chips. Chocolate bars tend to melt down more smoothly.
• Cream Cheese – I love the subtle tanginess and richness of cream cheese in this mousse. Take the cream cheese out of the fridge ahead of time to soften it.

How to Make Chocolate Mousse Cake

I love love love the chocolate cake recipe that’s the base for this mousse cake. It always makes fabulous sheet cakes, layer cakes, and Cupcakes. And it turns out that a half recipe makes the perfect thick, single-layer cake.

While the oven preheats, grease and line an 8-inch cake pan. Then, start by preparing your chocolate cake layer:

1. Combine the wet ingredients. First, beat together the sugar, oil, eggs, and vanilla, followed by the sour cream.
2. Add the dry ingredients. Next, sift the dry ingredients, including the cocoa powder, into a separate bowl. Add the dry ingredients to the wet batter, alternating with coffee, until just combined.
3. Bake. Transfer the cake batter to your prepared baking pan. Bake at 350ºF for 28-30 minutes, then take the cake out to cool completely.

Preparing the Mousse Layer

Before you whip the cream for your chocolate mousse, you’ll need to chill the bowl. Pop the metal mixing bowl from your stand mixer into the freezer while you prepare the ingredients:

1. Bloom the gelatin. Combine the gelatin powder with one tablespoon of cold water. Let it sit for a couple of minutes as it thickens into a gummy, solid state. Then, heat the gelatin in the microwave for 5-7 seconds just until it’s melted. Make sure and remove any pieces that didn’t melt down.

2. Melt the chocolate. Meanwhile, microwave the chocolate with heavy cream until melted. Then stir the liquid gelatin into your melted chocolate and set aside for now.

3. Prepare the whipped cream. Take your chilled bowl out from the freezer, and pour in the remaining heavy cream. Whip the cream using your stand mixer, then gradually beat in the powdered sugar until you get stiff peaks. Set this aside as well.

4. Prepare the cream cheese mixture. Next, beat the softened cream cheese together with sugar, cocoa, and vanilla. 

5. Combine. Fold the melted chocolate into the cream cheese until fully combined, followed by the whipped cream. Give everything a good final stir. Now, it’s time to assemble your chocolate mousse cake.

Assembling the Cake

I find it’s easiest to assemble this cake in an 8-inch spring form pan. I’ll usually bake the cake layer in a regular cake pan (see above) and then transfer it to a springform pan afterward. Here’s how to prepare the chocolate mousse cake:

1. Add the cake layer to the bottom of the pan. Sometimes you may want to torte the cake layer, meaning that you make it level. Because this is a single-layer cake, you may choose to leave the dome of the cake on. Either way is ok.
2. Pour the chocolate mousse filling over the cake and spread it evenly.
3. Finally, chill the cake in the fridge until the filling is set.

Adding the Toppings

Lastly, once the cake is fully set, we’ll top it with a silky smooth homemade ganache and pipe on some chocolate whipped cream. This is very easy to do:

1. Prepare the chocolate ganache. I recommend using a 3:1 ratio of heavy cream to chocolate. Heat the ingredients in the microwave in increments, until completely melted. Pour the ganache over the mousse layer and spread it out evenly with an angled spatula.
2. Make the whipped topping. Following the directions from earlier, prepare a new batch of chocolate whipped cream. I use a piping bag with an open-star tip to pipe a neat little border around the edge of the cake. But there really is no right way to decorate a cake! See below for more ideas.

Tips for Success

I firmly believe that anyone can make this dessert! The cake itself is pretty simple, as is the mousse. Just take it one step, one layer at a time, and you’ll be golden. Here are some more helpful tips for making a layered chocolate mousse cake:

• Remove any lumps in the gelatin. After you’ve microwaved the gelatin so that it’s liquid again, use a toothpick to fish out any leftover gummy bits. You definitely don’t want to be chewing on those!
• Use a cake collar. I use a cake collar for all my no-bake desserts, even when they’re in a pan (though a pan isn’t necessary). This is because the cake sometimes shrinks and leaves gaps at the edges, and it also makes it easier to cleanly remove the sides of the pan. I’ll tape a cake collar tightly around the cake layer before pouring over the mousse.
• If you don’t have an 8-inch springform pan, you can still assemble the cake in your regular baking pan. I highly recommend removing the cooled cake and lining the whole pan with plastic wrap or parchment paper before you add the cake back in to assemble. This way you can lift it out after it’s set.
• Leveling the cake. It’s up to you if you want to level (remove the dome) of the cake. I bake my cakes using bake-even stripes which help it to bake more level. So I usually just remove the very top layer to have a flat surface to work with. This is totally optional. You’ll find more helpful resources for this in my how to make layer cake post.

More Decorating and Variation Ideas

I use whipped cream to decorate this cake, but there are so many possibilities! You can just as easily pipe on swirls of Chocolate Buttercream or Oreo Frosting. Even Peanut Butter Frosting or Nutella Frosting would be delicious.

When it comes to decorating your chocolate mousse cake, try adding rainbow sprinkles, chocolate shavings, or chopped chocolate for garnish.

For more tips on decorating cakes, I have handy tutorials for How to Use a Piping Bag as well as How to Use and Decorate with Piping Tips. I also have a whole category dedicated solely to Mousse Cakes that’s a treasure trove of inspiration!

Does Mousse Cake Have to Be Refrigerated?

Yes. When it comes time to store your chocolate mousse cake, keep it covered airtight in the fridge and enjoy it within 2 days.

Can I Freeze Mousse Cake?

You can freeze this chocolate mousse cake for up to 2 months. I recommend freezing it while it’s still in the pan, wrapped tightly in a layer of plastic wrap, plus foil. Note that because the mousse recipe contains gelatin, it will not freeze completely solid. Thaw the chocolate mousse cake in the fridge before removing it from the pan and serving.

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More Easy Chocolate Cake Recipes to Try

• Chocolate Bundt Cake
• No-Bake Chocolate Marshmallow Pie
• Chocolate Mocha Cake 
• Super Moist Chocolate Cake
• Brownie Bottom Oreo Mousse Pie