Chocolate Mousse Cake

This post may contain affiliate sales links. Please read my disclosure policy.

This Chocolate Mousse Cake is a classic. It’s made up of three layers of moist chocolate cake divided by two layers of smooth and creamy chocolate mousse. The whole thing is covered in a light chocolate whipped cream frosting. Decadently delicious!

Rich & Decadent Chocolate Mousse Cake

There’s nothing quite like a rich, silky chocolate mousse. When combined with a moist, tender chocolate cake, you have the most wonderful cake – perfect for celebrations or satisfying a chocolate craving. This chocolate mousse cake is that chocolate cake. If you’ve ever made my Raspberry Chocolate Cake or my Peanut Butter Chocolate Cake, you’ve already made the cake itself before. It’s always a hit and super easy to make. It’s very similar to my favorite Chocolate Cake, but a touch more sturdy, which works well for the layering in this cake.

The three layers of chocolate cake are layered with a traditional, decadent, smooth chocolate mousse. There are no shortcuts here. We are using real-deal chocolate mousse. The whole thing is covered with chocolate-infused whipped cream frosting and garnished with chocolate sprinkles. Each aspect of this cake is loaded with chocolate flavor and is sure to wow the chocolate lovers in your life.

Why You’ll Love This Easy Mousse Cake

In case the words “chocolate mousse cake” didn’t already have you running to the kitchen without further thought, here’s a list of some of my favorite things about this cake. You have to try it.

• No fancy mixing method. The batter is so easy to whip up. You’ll be shocked at how quickly you will be popping the cakes in the oven.
• Rich and decadent. If you’re a chocolate lover like me, this cake will knock your socks off. It is brimming with rich chocolate flavor. Get that cold glass of milk ready.
• Moist. The cake layers themselves are perfectly moist, making this dessert a dream to sink your teeth into.
• Real chocolate mousse. Some chocolate mousse cakes will take shortcuts when it comes to the mousse filling. Not this one. The filling for this cake is a real-deal chocolate mousse. It’s incredibly rich and wonderfully silky smooth. Make a double batch and enjoy it as is!

What You’ll Need

Here’s a list of what you will need to make this sinfully delicious layer cake. Be sure to scroll to the recipe card below for exact measurements.

Chocolate cake

• All-purpose flour – Feel free to use your favorite 1:1 gluten-free flour instead.
• Sugar
• Natural unsweetened cocoa powder
• Baking soda and Baking powder – These two leavenings give you best texture and rise in this cake. It’s super tender, but also sturdy.
• Salt – Salt amplifies the flavors in the cake. Don’t leave it out.
• Milk – I suggest using whole milk or 2%. Dairy-free? Try a full-fat, unsweetened diary alternative such as oat milk or cashew milk.
• Vegetable oil – This cake uses oil instead of butter and is super moist.
• Vanilla extract
• Eggs – Be sure to use large size eggs.
• Hot water – For additional moisture without excess fat to weigh the cake down. The heat helps the cocoa bloom to give the chocolate cake a more intense flavor.

Chocolate mousse

• Egg yolks – These thicken the mousse and add to the rich and creamy texture.
• Sugar
• Heavy whipping cream – Should be cold in order to whip properly.
• Semi-sweet chocolate chips – I recommend semi-sweet chocolate. You could use dark chocolate. Milk chocolate might also be fine, but it doesn’t firm up quite as much, so the mousse may be a little softer.
• Powdered sugar – To help stabilize the whipped cream.

Chocolate whipped cream frosting

• Heavy whipping cream – The heavy whipping cream must be cold. Otherwise, it will not whip up and hold volume properly.
• Powdered sugar – To stabilize the whipped cream so that it never wilts.
• Natural unsweetened cocoa – Dutch-processed cocoa powder will work as well. Just note that the chocolate flavor will be more intense and a bit more bitter. It’ll also be darker in color.
• Vanilla extract
• Chocolate sprinkles

How to Make Chocolate Mousse Cake

Three cake layers, chocolate mousse filling, and chocolate whipped cream frosting. It might sound like a lot but I promise that if you take your time and follow my instructions closely, you will end up with an incredibly delicious, beautiful layer cake. Here’s how to make it. Scroll to the recipe card below for more detailed instructions.

Make the cake

• Prep. Preheat the oven to 350°F, line the bottoms of three 8-inch cake pans with parchment paper, and grease the sides.
• Combine the dry ingredients. Mix together the flour, sugar, cocoa, baking soda, baking powder, and salt.
• Combine the wet ingredients. Mix together the milk, vegetable oil, vanilla extract, and eggs.
• Combine the wet and dry ingredients. Add the wet ingredients to the dry ingredients and beat until well combined.
• Slowly add the hot water and mix to combine.

• Bake. Divide the batter between the cake pans. Bake for 22-25 minutes.
• Cool. Allow the cakes to cool in their pans for 2-3 minutes before transferring to a cooling rack to cool completely.

For the chocolate mousse

• Heat the egg yolks, sugar, and 1/2 cup of heavy whipping cream in the top of a double boiler over simmering water for 7-10 minutes, whisking constantly. Remove from the heat and set aside.
• Melt the chocolate. Microwave the chocolate chips in intervals of 10-15 seconds, stirring well between each, until melted and smooth.

• Whisk the chocolate into the egg yolk mixture. Let it cool to room temperature.
• Whip 1 1/4 cups of heavy whipping cream and powdered sugar until stiff peaks form.
• Put it all together. Fold 1/4 of the whipped cream into the chocolate mixture. Fold 1/4 of the chocolate mixture into the whipped cream. Fold the remaining chocolate mixture into the whipped cream.

Build the cake

• Level the tops of the chocolate cakes with a large serrated knife.
• Prepare the assembly pan. Use a clear cake collar (shown in the images) or an 8×3 inch cake pan (I recommend a springform pan) to build the cake. See the recipe card below for detailed instructions on what to do if you don’t have a springform pan.
• Stack and fill. Place the first cake layer in the bottom of the cake pan. Spread half of the chocolate mousse over the cake. Add the second cake layer and spread the remaining mousse over the cake before adding the final cake layer.

Frost and decorate

• Make the frosting. Whip the heavy whipping cream, powdered sugar, natural unsweetened cocoa, and vanilla extract on high speed until stiff peaks form.
• Remove the cake from the fridge and release it from the springform pan.
• Frost the outside of the cake with the chocolate whipped cream and pipe swirls around the outer top edge of the cake. Decorate with chocolate sprinkles.
• Refrigerate until ready to serve.

Tips for Success

Intimidated by making this multifaceted layer cake? Not to worry. I’ve got you covered with some helpful tips and tricks that will set you up for success. Here they come.

• Don’t over-mix. When combining the wet and dry ingredients, do not overmix the batter. This will cause the glutens in the flour to overdevelop and will leave you with a tough, dense cake.
• Scrape the sides of the bowl as you add ingredients and mix them in. This will help ensure that all of the ingredients make it into the batter and are incorporated evenly.
• Not too hot. When cooking the egg yolk mixture over the double broiler (for the mousse), don’t let the water boil or you’ll end up with scrambled eggs. You just want the water to be at a simmer. I suggest lifting the bowl occasionally to release steam from underneath.
• Keep it moving. When cooking the egg yolk mixture for the mousse, it is important that you whisk continuously. This not only helps incorporate air and volume into the mixture but it will also help keep you from ending up with scrambled eggs.
• Be gentle with the mousse. When folding the chocolate mixture into the whipped cream and vice versa, do so gently with a rubber spatula so as not to knock the air out of the mousse.
• Let the chocolate cool. Be sure that the egg yolk-chocolate mixture has cooled completely before folding it into the whipped cream for the mousse. Otherwise, it will melt the whipped cream and knock the volume out of it.
• Cold heavy cream. Be sure that the heavy whipping cream used to make the frosting is cold. It will whip up and hold volume better.
• Let the cakes cool. Before stacking, filling, and frosting the cake it is crucial to allow the cake layers to cool. Otherwise, the mousse and the frosting will slide right off.
• No mess assembly. I highly recommend using a springform pan here but, if you do not have one, assemble the cake on a cardboard cake circle with the help of a clear cake collar. You can use an 8×3 inch cake pan instead but make sure to prepare it properly. Place a large piece of plastic wrap in the cake pan so that it covers the bottoms and sides. This will help you lift the cake out of the pan. Line the bottom (over the plastic wrap) with a cardboard cake circle and line the sides of the pan with parchment paper. The parchment paper should stick up above the top edge of the pan to prevent overflow.

Can The Mousse Be Prepared in Advance?

I don’t recommend making the mousse in advance of adding it to the cake. It will firm up in the fridge and you’d have to stir it back up before using it later, which can cause it to deflate. You can definitely make the cake layers in advance though. And with the all the moisture in the cake and chocolate mousse, you can easily make the full cake a day or so in advance. It holds up very well.

How to Store This Chocolate Mousse Layer Cake

If you find yourself with leftover chocolate mousse cake, store it in an airtight cake carrier or let it chill for a couple of hours in the refrigerator before wrapping the whole thing in a double layer of plastic wrap. Use toothpicks to prop the plastic away from any decorations. Already sliced it? Arrange the slices in a single layer in an airtight container. Whatever method you choose, you can store the cake in the refrigerator for 4 to 5 days.

You can also freeze this cake. Pop it in the freezer for a couple of hours to firm up before wrapping it in a double layer of plastic wrap and storing it in the freezer for up to 3 months. If you already sliced the cake, arrange the slices in a single layer in an airtight container and store it in the freezer for up to 3 months. Let the cake thaw in the refrigerator before serving.

More Decadent Chocolate Cakes

In a chocolate kind of mood? Good. Me too. Always. Here are a few other heavenly chocolate cakes. Pour yourself a glass of cold milk and take yourself on a chocolate cooking spree.

• Flourless Chocolate Cake
• Orange Chocolate Cake
• German Chocolate Cake
• The Best Chocolate Cake Recipe
• Chocolate Lava Cake
• Chocolate Oreo Cake

Watch How It’s Made

Read Transcript

Print