Chocolate Raspberry Mousse Cake

4.86 from 27 ratings

Chocolate Raspberry Mousse Cake

This chocolate raspberry mousse cake has the perfect balance of tart and sweet! Its moist chocolate cake layers are filled with fluffy chocolate mousse, tart raspberry jam, and fresh raspberries.

Prep Time30

Cook Time25

Additional Time2 30

Total Time3 25

Course: Cakes

Cuisine: American

Servings: 24

Calories: 581kcal

Author: Chelsey White

Equipment

Ingredients

Chocolate Mousse

3/4 cup good-quality dark chocolate chips 120g
1/2 cup warm water 120g
1/3 cup unsweetened cocoa powder, sifted 33g
1 1/2 cups heavy whipping cream, cold 360g
1 cup powdered sugar 125g
2 tsp vanilla extract or vanilla bean paste 10g
pinch fine salt less than 1/8 tsp

Moist Chocolate Cake Recipe

2 1/2 cups all-purpose flour 325g
2 1/2 cups granulated sugar 500g
1 cup unsweetened cocoa powder, sifted 100g
2 1/2 tsp baking powder 10g
2 tsp baking soda 12g
1 tsp fine salt 6g
1 1/4 cup warm water 300g
1 1/4 cup buttermilk, room temperature 300g
2/3 cup vegetable or canola oil 145g
3 large eggs, room temperature 156g

Chocolate Buttercream Frosting

1 1/2 cup (3 sticks) unsalted butter, room temperature 336g
1/2 cup unsweetened cocoa powder, sifted 40g
1 tsp vanilla extract or vanilla bean paste 5g
1/4 tsp fine salt 1g
3 1/2 cups powdered sugar 454g
1/3 cup heavy whipping cream, room temperature 90g
1 cup dark or milk chocolate chips, melted and cooled 160g

Cake Filling & Decoration

1 cup raspberry jam 350g
3 cups fresh raspberries, divided - optional 375g

Instructions

Chocolate Mousse Filling

Make the chocolate mousse first, so it has time to chill. Or better yet, make this mousse in advance! It can be made 1-2 days ahead of time.
Melt 3/4 cup of chocolate chips by placing them in a medium-sized, heat-proof bowl. Heat in 20-30 second increments in the microwave, stirring after each increment until the chocolate is completely melted and smooth. If you don't have a microwave, you can also use a double boiler.
In a small bowl, whisk together 1/2 cup of warm water and 1/3 cup of cocoa powder. Pour into the melted chocolate and whisk together until smooth. The mixture should be somewhat thick. Set aside.
In a large bowl or the bowl of a stand mixer fitted with a whisk attachment, add 1 1/2 cups of cold heavy cream, 1 cup of powdered sugar, 2 tsp of vanilla extract, and a pinch of fine salt.
Mix on medium-high speed until the whipped cream starts to gather in the whisk attachment and you can see texture around the edges of the bowl. The whipped cream should be thick and able to keep its shape. This usually takes about 2 1/2 to 3 minutes in my stand mixer.
Gently fold the chocolate mixture into the whipped cream using a rubber spatula. Use the spatula to swoop around the sides of the bowl and pull through the center like I show in the video of this recipe. Be careful not to over-mix the mousse, or it will become deflated and lose its structure.
Then cover the mousse with plastic wrap and chill in the refrigerator for at least 2 hours.

Chocolate Cake Layers

Preheat the oven to 350F / 175C. Grease and line 4, 8-inch cake pans.
Whisk together 2 1/2 cups of all-purpose flour, 2 1/2 cups of granulated sugar, 1 cup of unsweetened cocoa powder, 2 1/2 tsp baking powder, 2 tsp baking soda, and 1 tsp fine salt into a large bowl.
Pour in 1 1/4 cups of warm water, 1 1/4 cups buttermilk, 2/3 cup of oil, and 3 eggs into a separate bowl and whisk together until fully incorporated.
Mix the wet ingredients into the dry ingredients just until they're incorporated into the batter.
Divide the batter evenly between the prepared cake pans, and bake for about 23-26 minutes or until a toothpick comes out with a few moist crumbs.
Remove the cake layers from the oven and let them cool in the pans for about 10 minutes. Gently run an offset spatula around the rim of the cake pans to loosen them, then flip them into wire racks to finish cooling.
Once cooled, use a serrated knife to level the top of each cake layer. If you are making these in advance, wrap and freeze them at this point.

Chocolate Buttercream Frosting

Beat 1 1/2 cups (3 sticks) of butter on a medium speed for 30 seconds with a paddle attachment until smooth.
Add in 1/2 cup of sifted unsweetened cocoa powder, 1 tsp of vanilla extract, and 1/4 tsp of salt. Mix on low until the ingredients are fully incorporated.
Slowly mix in 3 1/2 cups of powdered sugar. Halfway through, add 1/3 cup of heavy cream to make the frosting easier to mix.
Then mix in 1 cup of cooled, melted dark chocolate on a low speed until the ingredients are fully incorporated. Cover with plastic wrap to prevent crusting and set aside.

Assembling This Chocolate Raspberry Mousse Cake

Stack and frost cake layers on a greaseproof cakeboard using a dab of chocolate buttercream to help stick the first cake layer to the board.
As you assemble the cake, spread about 1/3 cup of raspberry jam on top of the first 3 cake layers. Then spread about 1/3 of the chocolate mousse in an even layer on top of the jam. If desired, gently press about 2/3 cup of fresh raspberries into the mousse. Flip the top cake layer upside down to make it easier to frost.
Repeat with the remaining cake layers. Smooth any overhanging mousse around the cake with a large offset spatula, then freeze the cake for about 10 minutes in the freezer. This helps the mousse and filling firm up so the cake is easier to frost.
Carefully cover the cake with a thick, even layer of chocolate buttercream and use an offset spatula or the back of a spoon to make some cute swoops around the cake. Top with a semicircle of fresh raspberries and enjoy!

Video

Notes

My Tips for Making the Best Chocolate Raspberry Mousse Cake

When making the chocolate mousse, chill your mixing bowl and whisk attachment in the freezer. It makes it easier and quicker to whip up the whipped cream for the mousse.
Ingredients at room temp mix together better! Set out any cold ingredients ahead of time.
Properly measure your flour (spoon into the cup measure, then level). Or better yet, use a kitchen scale to measure your dry ingredients.
Mix your cake batter just until the ingredients are incorporated. This will ensure your cake layers are tender and fluffy.
Use a scale to weigh your cake pans as you fill them. Making sure each pan has the same amount of batter helps the cake layers bake to the same height and bake more evenly.
Level your room temperature or thawed cake layers with a serrated knife to make them easier to stack.
Chill your cake layers in the freezer for about 20 minutes before assembling the cake. It makes it so much easier to stack and frost them!

Making This Chocolate Raspberry Mousse Cake in Advance & Storage Tips

Make your cake layers in advance and freeze them. It breaks the process up and makes it more approachable.
The chocolate mousse can also be made in advance! It can be made up to 2 days in advance and stored in the fridge.
Make your chocolate frosting ahead of time or save any leftover frosting! It can be stored in an airtight container in the fridge for up to a month.
This frosting can also be stored in the freezer for up to 3 months! Just be sure to give it a good stir once it comes to room temperature to make it nice and smooth again.
A frosted cake can last in the fridge for up to 2 days. I don't recommend storing it longer than that, as the raspberries can start to spoil.

Nutrition