Name: Chocolate Mousse Brownies
Prep time: 25 min
Cook time: 25 min
Total time: 2 h 50 min
Cuisine: American
Ingredients: 1/2 cup (115 g) unsalted butter; 3/4 cup (150 g) granulated sugar; 2 large eggs; 1 teaspoon vanilla extract; 1/2 cup (50 g) unsweetened cocoa powder; 3/4 cup (95 g) all-purpose flour; 1/4 teaspoon salt; 1/4 teaspoon baking powder (optional, for slightly lighter brownie texture); 1/2 cup (85 g) semi‑sweet or dark chocolate chips/chunks (optional, for extra fudge); For the mousse topping:; 4 oz (about 115 g) semi‑sweet or dark chocolate, chopped; 1 cup (240 ml) heavy whipping cream; 2 tablespoons powdered sugar (optional, for extra sweetness); 1 teaspoon unflavored gelatin (optional, for firmer mousse); 1 tablespoon water (if using gelatin)

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Chocolate Mousse Brownies are a decadent dessert I turn to when I want to impress without overcomplicating things. With a rich, fudgy brownie base and a smooth, airy chocolate mousse topping, these layered bars are the perfect blend of dense and light, sweet and indulgent. Each bite feels like a slice of chocolate heaven.

Why You’ll Love This Recipe

I love how these brownies combine two incredible textures in one dessert—the deep, chewy richness of brownies and the silky lightness of mousse. It’s an elegant treat that looks fancy but is surprisingly simple to make. They’re perfect for holidays, dinner parties, or whenever I want a show-stopping chocolate dessert. Chocolate Mousse Brownies

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

For the Brownie Base:

Unsalted butter
Granulated sugar
Eggs
Vanilla extract
Cocoa powder
All-purpose flour
Salt
Baking powder (optional, for a slightly lighter brownie)
Semi-sweet or dark chocolate (chopped or chips, optional)

For the Chocolate Mousse:

Semi-sweet or dark chocolate
Heavy whipping cream
Powdered sugar (optional, for extra sweetness)
Gelatin (optional, for a firmer set)
Water (if using gelatin)

Directions

I begin by preheating the oven to 350°F (175°C) and lining a baking pan with parchment paper.

For the brownies:
I melt the butter in a saucepan, remove it from the heat, then stir in the sugar, eggs, and vanilla.
Next, I sift in the cocoa powder, flour, salt, and baking powder if using, and stir until just combined.
If I’m using chocolate chips or chunks, I fold them into the batter.
I pour the batter into the prepared pan and bake for about 20–25 minutes, until a toothpick comes out with a few moist crumbs.
I let the brownies cool completely before adding the mousse layer.

For the mousse:
I melt the chocolate in a heatproof bowl over simmering water or in the microwave in short bursts. I let it cool slightly.
I whip the heavy cream to soft peaks, adding powdered sugar if I want it a little sweeter.
If I’m using gelatin, I bloom it in water and melt it gently before stirring it into the melted chocolate.
I fold the whipped cream into the cooled chocolate in batches, creating a smooth and airy mousse.

I spread the mousse evenly over the cooled brownies and refrigerate for at least 2 hours, or until the mousse is set.

I slice into bars and serve chilled, optionally topping with chocolate shavings, whipped cream, or berries.

Servings and timing

This recipe makes about 12 brownies.
Prep time: 25 minutes
Bake time: 25 minutes
Chill time: 2 hours
Total time: 2 hours and 50 minutes

Variations

Sometimes I add espresso powder to the brownie batter for a mocha twist.

For a minty version, I mix a few drops of peppermint extract into the mousse.

I occasionally make a white chocolate mousse instead for a layered contrast.

If I want crunch, I sprinkle chopped nuts or crushed cookies between the brownie and mousse layers.

I’ve also topped them with a chocolate ganache layer for extra richness.

Storage/Reheating

I store the brownies in the fridge in an airtight container for up to 4 days.

These freeze well too—I just wrap each one individually and thaw in the fridge before serving.

I don’t recommend reheating, since the mousse is best served cold. Chocolate Mousse Brownies

FAQs

Can I use a boxed brownie mix?

Yes, when I’m short on time, I use my favorite boxed mix for the base and just make the mousse from scratch.

Do I need to use gelatin in the mousse?

No, but it helps the mousse set firmer if I’m serving these at a warm event or want cleaner slices.

How do I get clean cuts?

I chill the brownies well and use a sharp knife dipped in hot water and wiped dry between cuts.

Can I use milk chocolate?

Yes, but I find dark or semi-sweet chocolate gives the best balance of sweetness and richness for the mousse.

Can I make them in advance?

Absolutely. I often make these a day ahead—they hold up beautifully and the flavors deepen overnight.

Conclusion

Chocolate Mousse Brownies are one of those desserts that feel luxurious with every bite. Whether I’m making them for a celebration or just craving something extra special, they always deliver. With their rich base and light, creamy topping, they’re a chocolate lover’s dream in bar form.