Introduction

Mousse brownies are a decadent dessert combining a rich, fudgy brownie base with a light and airy chocolate mousse layer, topped with a glossy ganache. This elegant treat is perfect for impressing guests or indulging your chocolate cravings at home.

Three square pieces of chocolate brownies are stacked on a white plate, each with two layers: a dense, dark brown base with a rich, moist texture, and a thick, light brown, creamy frosting on top that looks soft and airy with gentle swirls. The edges of the brownies are slightly crumbly, and there are a few small crumbs scattered on the plate. The background shows a white marbled texture with soft natural light coming from the side. Photo taken with an iphone --ar 4:5 --v 7

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

Instructions

Step 1: Preheat the oven to 350°F (175°C) and line an 8×8-inch (20×20 cm) square baking pan with parchment paper, leaving a slight overhang on the sides for easy removal.
Step 2: In a large bowl, whisk together the melted butter, granulated sugar, eggs, and vanilla extract until smooth and well combined.
Step 3: Sift in the cocoa powder, flour, salt, and baking powder. Gently fold the dry ingredients into the wet mixture just until no streaks remain. Do not overmix.
Step 4: Pour the batter into the prepared pan and smooth the top with a spatula. Bake for 20 to 25 minutes until a toothpick inserted into the center comes out with a few moist crumbs. Let the brownie base cool completely in the pan.
Step 5: Heat the milk in a small saucepan over low heat until just steaming. Pour it over the chopped chocolate in a heatproof bowl. Let sit undisturbed for 2 minutes, then stir until fully melted and smooth. Let the mixture cool to room temperature.
Step 6: In a separate bowl, beat the chilled heavy cream and powdered sugar until soft peaks form.
Step 7: Stir a spoonful of whipped cream into the cooled chocolate mixture to loosen it. Gently fold the remaining whipped cream into the chocolate until fully blended and airy, being careful not to deflate the mousse.
Step 8: Spread the chocolate mousse evenly over the cooled brownie base using a spatula. Refrigerate the pan for at least 2 hours, or until the mousse is set.
Step 9: Place the chopped chocolate in a heatproof bowl. Heat the heavy cream in a small saucepan until it begins to simmer. Pour the hot cream over the chocolate and let sit for 2 to 3 minutes. Stir until smooth and glossy.
Step 10: Pour the ganache over the chilled mousse layer and smooth the surface with an offset spatula. Return the pan to the refrigerator for 1 hour, or until the ganache is firm.
Step 11: Once fully set, lift the dessert out of the pan using the parchment overhang. Slice with a clean, sharp knife, wiping between cuts for neat edges. Serve and enjoy.

Tips & Variations

Use high-quality chocolate for deeper flavor in both mousse and ganache.
For a mocha twist, add 1 tsp instant espresso powder to the brownie batter.
Ensure the heavy cream is well chilled before whipping for best volume.
To make smaller servings, cut brownies into bite-sized squares and serve chilled.

Storage

Store mousse brownies covered in the refrigerator for up to 3 days to keep the mousse and ganache fresh. Before serving, let them sit at room temperature for about 10 minutes for a softer texture. Avoid freezing, as the mousse texture may be compromised upon thawing.

How to Serve

A square piece of chocolate dessert with two clear layers sits on a silver spatula; the bottom layer is a dark, dense brownie, while the top layer is a thick, smooth light brown frosting spread evenly across the surface. This piece is being lifted from a white baking pan that holds the rest of the dessert, which is cut into square pieces with visible clean edges. The background and surface show a white marbled texture, and in the top corner, a few stacked white plates and a white cup are slightly visible. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I make the mousse brownies ahead of time?

Yes, mousse brownies are ideal for making a day ahead. This allows the mousse and ganache layers to set perfectly, enhancing the flavors and texture.

What if I don’t have an 8×8-inch pan?

You can use a similarly sized pan, such as a 9×9-inch, but the layers may be slightly thinner and baking times for the brownie base might need adjustment. Keep an eye on the brownie doneness with a toothpick test.