Name: Chocolate Mousse Brownies
Prep time: 30 min
Cook time: 30 min
Total time: 4 h
Cuisine: American
Ingredients: ½ cup (115 g) unsalted butter, melted; 1 cup (200 g) granulated sugar; 2 large eggs; 1 tsp vanilla extract; ⅓ cup (40 g) unsweetened cocoa powder; ½ cup (65 g) all-purpose flour; ¼ tsp salt; ¼ tsp baking powder; 1½ cups (350 ml) heavy whipping cream, chilled; 8 oz (225 g) semisweet chocolate, finely chopped; 3 tbsp (45 ml) milk; 2 tbsp (25 g) powdered sugar; 4 oz (115 g) semisweet chocolate, finely chopped; ½ cup (120 ml) heavy cream

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A luscious layered dessert combining fudgy brownies, silky chocolate mousse, and a glossy ganache topping. I love how each bite delivers rich textures and deep chocolate flavor, perfect for an indulgent treat.

Chocolate Mousse Brownies

Why You’ll Love This Recipe

I love this recipe because it combines three irresistible chocolate layers into one show-stopping dessert. The dense brownie base gives sturdy support, the light mousse adds elegance, and the shiny ganache ties it all together. It’s easier than it looks but feels impressively decadent when served.

ingredients

(Hint: Check out the full list of ingredients and measurements in the recipe card below.)

For the Brownie Base:

½ cup (115 g) unsalted butter, melted
1 cup (200 g) granulated sugar
2 large eggs
1 tsp vanilla extract
⅓ cup (40 g) unsweetened cocoa powder
½ cup (65 g) all-purpose flour
¼ tsp salt
¼ tsp baking powder

For the Chocolate Mousse:

1½ cups (350 ml) heavy whipping cream, chilled
8 oz (225 g) semisweet chocolate, finely chopped
3 tbsp (45 ml) milk
2 tbsp (25 g) powdered sugar

For the Ganache Topping:

4 oz (115 g) semisweet chocolate, finely chopped
½ cup (120 ml) heavy cream

directions

Make the Brownie Base
- I preheat the oven to 350 °F (175 °C) and line an 8×8-inch (20×20 cm) pan with parchment paper.
- In a bowl, I whisk together melted butter, sugar, eggs, and vanilla until smooth.
- Then I sift in cocoa powder, flour, salt, and baking powder and gently fold until just combined—no overmixing.
- I pour the batter into the pan, smooth it out, and bake for 20–25 minutes. A toothpick should come out with a few moist crumbs. I let it cool completely in the pan.
Prepare the Chocolate Mousse
- I heat the milk until just steaming and pour it over the chopped chocolate. After letting it sit for 2 minutes, I stir until smooth and let it cool to room temperature.
- In another bowl, I whip the heavy cream with powdered sugar until soft peaks form.
- I gently fold the cooled chocolate mixture into the whipped cream, careful not to deflate it.
- I spread the mousse over the cooled brownie layer and refrigerate for at least 2 hours, until set.
Top with Ganache
- I place the chopped chocolate in a bowl, simmer the heavy cream, and pour it over the chocolate. After waiting 2–3 minutes, I stir until glossy.
- I pour the ganache over the mousse and spread it evenly.
- I refrigerate another hour until the ganache is firm.

Servings and timing

Servings: 9 squares (8×8-inch pan, cut into 3×3 grid)
Prep time: ~30 minutes
Bake/make time: ~30 minutes
Chill time: 3+ hours
Total time: ~4 hours

storage/reheating

I store these brownies covered in the refrigerator for up to 4 days. For the best texture, I let them come to room temperature for 15–20 minutes before serving. I don’t recommend reheating—they’re best served chilled.

FAQs

What type of chocolate should I use for the mousse and ganache?

I prefer semisweet chocolate (around 60% cacao) for a balanced sweetness. Bittersweet works fine if you like it less sweet; milk chocolate makes it noticeably sweeter and lighter.

Can I make this ahead of time?

Absolutely. I often make it a day ahead and refrigerate overnight. Just add an extra 30 minutes of chill time so the layers set perfectly.

Can I freeze the brownies?

Yes. I freeze individual squares in an airtight container. They last about 2 months. To serve, I thaw in the fridge overnight, then let them warm at room temperature for a bit.

What if I don’t have powdered sugar?

I use powdered sugar for a smooth mousse, but you can substitute with 2 tbsp of fine granulated sugar. Just whisk it well into the whipped cream, though the texture may be slightly grainier.

Can I make these dairy-free or vegan?

I haven’t tested a full vegan version, but I’ve swapped the heavy cream with coconut cream and used dairy-free chocolate for the mousse and ganache. The brownies adapt well with dairy-free substitutes. Texture will be a bit different, but still delicious.

Conclusion

I’m always impressed by how elegant these Chocolate Mousse Brownies turn out with minimal effort. They’re rich, creamy, and striking—perfect for special occasions or when I want to treat myself. Once I mastered the layers, I never looked back.