Chocolate Mousse Brownies Recipe

Why You’ll Love This Recipe

What I love about this recipe is the perfect balance between textures and flavors. The brownie base is dense and fudgy, the chocolate mousse is light and airy, and the ganache topping adds an irresistible richness. Each bite is a heavenly experience with just the right amount of sweetness and a deep chocolate flavor. Plus, it’s not overly complicated, though it does take some time to chill. It’s a dessert that I can prepare in advance, making it ideal for parties, special occasions, or a weekend indulgence.

Ingredients

For the Brownie Base:

1/2 cup (115g) unsalted butter, melted

1 cup (200g) granulated sugar

2 large eggs

1 tsp vanilla extract

1/3 cup (40g) unsweetened cocoa powder

1/2 cup (65g) all-purpose flour

1/4 tsp salt

1/4 tsp baking powder

For the Chocolate Mousse:

1 1/2 cups (350ml) heavy whipping cream, chilled

8 oz (225g) semisweet chocolate, finely chopped

3 tbsp (45ml) milk

2 tbsp (25g) powdered sugar

For the Ganache Topping:

4 oz (115g) semisweet chocolate, finely chopped

1/2 cup (120ml) heavy cream

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

Directions

Step 1: Make the Brownie Base

Preheat the oven to 350°F (175°C) and line an 8×8-inch (20×20 cm) baking pan with parchment paper.

In a mixing bowl, I whisk together the melted butter, granulated sugar, eggs, and vanilla extract until smooth.

Sift in the cocoa powder, flour, salt, and baking powder. I gently fold the dry ingredients into the wet ingredients until just combined—being careful not to overmix.

I pour the brownie batter into the prepared pan and smooth it out with a spatula.

I bake the brownies for 20-25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Once done, I let the brownie base cool completely in the pan.

Step 2: Prepare the Chocolate Mousse

I heat the milk in a small saucepan until it’s just steaming (but not boiling). I pour it over the chopped semisweet chocolate in a heatproof bowl, letting it sit for about 2 minutes before stirring until the chocolate is fully melted and smooth. I then let it cool until it’s no longer warm but still fluid (about room temperature).

In a separate bowl, I whip the chilled heavy cream with powdered sugar until soft peaks form.

I gently fold the cooled chocolate mixture into the whipped cream until it’s fully incorporated. I make sure to be careful not to deflate the mousse.

Once the mousse is ready, I spread it evenly over the cooled brownie base.

I refrigerate the assembled dessert for at least 2 hours, or until the mousse is set.

Step 3: Top with Ganache

For the ganache, I place the chopped semisweet chocolate in a heatproof bowl. I heat the heavy cream in a small saucepan until it begins to simmer, then pour it over the chocolate. I let it sit for 2-3 minutes before stirring until smooth and glossy.

I pour the ganache over the mousse layer and spread it evenly with an offset spatula.

Finally, I refrigerate the brownies for another hour, or until the ganache is firm.

Servings and Timing

Servings: 12

Prep Time: 30 minutes

Cooking Time: 3 hours (includes chilling time)

Total Time: 3 hours 30 minutes

Variations

White Chocolate Mousse: If I prefer a different flavor profile, I can replace the semisweet chocolate with white chocolate for a sweeter, creamier mousse.

Add Some Crunch: To add some texture, I can sprinkle crushed nuts (like walnuts or almonds) or crushed cookies over the mousse before adding the ganache topping.

Flavor Infusions: For a unique twist, I can infuse the ganache or mousse with flavors like orange zest or coffee for a deeper, more complex flavor.

Storage/Reheating

These Chocolate Mousse Brownies can be stored in an airtight container in the fridge for up to 3 days. I recommend serving them chilled as they hold their shape better, but they can also be brought to room temperature if preferred. Since the mousse is so creamy, they’re best enjoyed within a few days.

FAQs

Can I make these brownies ahead of time?

Yes, this is an ideal make-ahead dessert. I can prepare them the day before and let them chill overnight, which also helps the flavors develop.

Can I substitute the semisweet chocolate?

Yes, I can use dark chocolate or milk chocolate instead of semisweet, but keep in mind the sweetness and richness will vary. Dark chocolate will give a deeper flavor, while milk chocolate will be sweeter.

Can I freeze these brownies?

I don’t recommend freezing them because the mousse layer may lose its texture when thawed. However, I can freeze just the brownie base before adding the mousse and ganache if I want to prep it ahead of time.

How can I tell when the brownie base is done?

I test the brownies by inserting a toothpick into the center—if it comes out with a few moist crumbs (not wet batter), they’re done. Remember, the brownie base will continue to set as it cools.

What can I serve with these brownies?

These brownies are rich on their own, but I love serving them with a scoop of vanilla ice cream or a drizzle of caramel sauce for an extra indulgent treat.

Conclusion

Chocolate Mousse Brownies are the ultimate dessert for any chocolate lover. With their fudgy brownie base, creamy mousse filling, and glossy ganache topping, these brownies are a decadent treat that’s sure to impress. While the recipe takes a little time to chill, the result is more than worth the wait. It’s a dessert that brings together the best of both worlds—brownies and mousse—into one irresistible bite!

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