Why You’ll Love This Brownie Chocolate Mousse Cake
Chocolate mousse and brownies are soulmates. The contrast between the silky mousse and the gooey, crispy brownie is to die for! This chocolate mousse cake has a brownie base made from my all-time favorite brownie recipe and is topped with an egg-based chocolate mousse that’s easy to make.
As if that isn’t enough to make you drool, what really elevates this chocolate mousse cake is the delicate decorations of fresh berries and buttercream. It not only looks beautiful but also tastes incredibly delicious, making it hard to resist a second… or third… or fourth piece 😉

Which Baking Pan Should You Use?
I baked my chocolate mousse cake in a round springform pan because I think it the round shape gives the cake such a pretty look, but you can certainly use a square pan if you prefer.
For the best-looking mousse, use a pan with removable sides, like a springform pan or an adjustable baking ring, which comes in both round and square versions. You may also consider lining the inside of your pan with acetate for a perfectly smooth mousse finish.
The chocolate mousse cake needs to chill for at least 6 hours to set completely—overnight is even better. When it’s time to remove the springform or adjustable ring, run a sharp knife around the inside edge of the pan before loosening it to ensure a clean release. This step isn’t necessary if you’ve lined the pan with acetate sheets.


Decorating Your Chocolate Mousse Cake
You can decorate the chocolate mousse cake however you like. If you want to decorate it like I did, you’ll need:
- Fresh blueberries
- Fresh blackberries
- Chocolate buttercream
- Royal icing (purple and white)
- Chopped milk chocolate
The small purple flowers made from royal icing are easy to create using a flower piping tip. Wilton offers a variety of tips; I used Wilton 224 tip. I piped the flowers onto parchment paper, let them harden, and then placed them on the cake.
Enjoy your baking and decorating! This chocolate mousse cake is sure to impress both visually and taste-wise, making it a perfect dessert for any occasion.

More Delicious Cakes

Recipe
Brownie Chocolate Mousse Cake With Fresh Berries
Udstyr
- Purple food coloring
- Piping tip Wilton 224
- Round pan 26 cm (10 inches)
- Piping bags
Ingredients
Brownies:
- 1 batch of my brownie recipe
Chocolate mousse:
- 250 ml heavy cream
- 4 egg yolks (preferably pasteurized)
- 30 g sugar
- 70 g quality dark chocolate
- 30 g quality dark chocolate
Purple and white royal icing:
- Powdered sugar
- Egg whites (preferably pasteurized)
- Purple coloring
Chocolate buttercream:
- 40 g dark chocolate
- 40 g butter (room temperature)
- 1/2 tsp vanilla
- 200 g powdered sugar (approx.)
- 2 tbsp milk
To decorate:
- Fresh blueberries
- Fresh blackberries
- Milk chocolate (chopped or chips)
Instructions
Brownie base:
- Start by making a batch of my brownies recipe. Bake it in a greased round pan, 26-27 cm (10-10.5 inches) in diameter.1 batch of my brownie recipe
- Allow the brownies to cool completely in the pan.
Chocolate mousse:
- Whip the heavy cream in a bowl using an electric mixer until it forms stiff peaks. Place the whipped cream in the fridge to keep it cool.250 ml heavy cream
- In another bowl, whisk the egg yolks and sugar together until they become light and fluffy.4 egg yolks, 30 g sugar
- Roughly chop the dark chocolate, then melt 70 g quality dark chocolate in the microwave or over a double boiler. Stir the remaining 30 g quality dark chocolate into the melted chocolate until it’s fully melted and smooth.70 g quality dark chocolate
- Pour the melted chocolate into the egg mixture. Gently fold the chilled whipped cream into the chocolate and egg mixture a little at a time, ensuring the chocolate is evenly incorporated to create a smooth mousse.
- Spread the chocolate mousse over the cooled brownie base in the pan. Refrigerate the mousse cake for at least 6 hours, or preferably overnight, to let it set.
- When it’s time to decorate, you can either do so while the cake is still in the pan or remove it first. To release the cake from the pan, run a sharp knife along the inside edges to ensure a clean release.
Purple and white royal icing:
- For a decorative touch, you can pipe small flowers using royal icing in shades of purple and white. To make the royal icing, mix a small amount of egg white into powdered sugar until it forms a thick icing.Powdered sugar, Egg whites
- Set aside a portion of the icing to remain white, and put it into a small piping bag with a round tip (or just snip a small hole in the bag).
- Add a bit of purple food coloring to the remaining icing and stir until the color is evenly distributed.Transfer the purple icing to a piping bag fitted with a flower tip, such as Wilton 224.Purple coloring
- Pipe purple flowers onto a sheet of parchment paper, then add a small dot of white icing in the center of each flower.
- Allow the flowers to dry at room temperature for about 1 to 2 hours until they harden.
Chocolate buttercream:
- Chop the chocolate and melt it in the microwave or over a double boiler, making sure it doesn’t burn. Let the chocolate cool for about 10 minutes.40 g dark chocolate
- Beat the butter and vanilla in a stand mixer or with an electric hand mixer until fluffy.40 g butter, 1/2 tsp vanilla
- Beat the butter and vanilla in a stand mixer or with an electric hand mixer until fluffy. Gradually add the powdered sugar and milk while continuing to beat the mixture. Slowly stir in the melted chocolate until it’s fully incorporated, and the buttercream is light brown.200 g powdered sugar, 2 tbsp milk
- Adjust the consistency with more powdered sugar or milk as needed to make the buttercream pipeable.
- Transfer the buttercream to a piping bag with a round tip (or simply snip a hole in the bag).
- Take the chocolate mousse cake out of the fridge and pipe large dollops of buttercream on top, as shown in the picture, or get creative with your design.
To decorate:
- For the final touches, rinse some blueberries and blackberries and use them to decorate the cake along with chopped milk chocolate and the royal icing flowers.Fresh blueberries, Fresh blackberries, Milk chocolate