Description
Indulge in these decadent Chocolate Mousse Brownies featuring a fudgy brownie base topped with a rich, airy chocolate mousse. Perfectly balanced with sweet mini marshmallows melted into the mousse layer and finished with an optional chocolate syrup drizzle, this dessert is a delightful treat for chocolate lovers and a show-stopping finale for any occasion.
Ingredients
Brownie Base
- 4 ounces semisweet chocolate baking bar, chopped
- ¼ cup salted butter
- ⅓ cup vegetable oil
- 1½ cups granulated sugar
- 2 eggs, room temperature
- 2 teaspoons pure vanilla extract
- ¾ cup all purpose flour, spooned and leveled
- ½ cup unsweetened dutch processed cocoa powder
- ½ teaspoon baking powder
- ½ teaspoon table salt
Chocolate Mousse
- 4 ounces semisweet chocolate baking bar, chopped
- 1 cup mini marshmallows
- ¼ cup + 1 tablespoon whole milk
- 1¼ cups cold heavy cream
- Chocolate syrup for drizzling (optional garnish)
Instructions
- Preheat and Prepare: Preheat your oven to 350°F (175°C) and line a 9×9 inch baking pan with parchment paper, leaving an overhang on the sides to easily lift out the brownies later.
- Melt Chocolate and Butter: In a microwave-safe bowl or over a double boiler, melt 4 ounces of chopped semisweet chocolate and ¼ cup salted butter in 20-second intervals, stirring until smooth. Stir in ⅓ cup vegetable oil until fully combined.
- Mix Sugar and Chocolate: In a large mixing bowl, add 1½ cups granulated sugar. Whisk in the chocolate and butter mixture until thoroughly combined; the batter will be thick.
- Add Eggs and Vanilla: Whisk in the 2 eggs one at a time, ensuring each is incorporated before adding the next. Do not overbeat to avoid adding excess air. Stir in 2 teaspoons pure vanilla extract.
- Incorporate Dry Ingredients: Sift together ¾ cup all-purpose flour, ½ cup unsweetened dutch processed cocoa powder, ½ teaspoon baking powder, and ½ teaspoon salt over the wet mixture. Gently fold with a spatula until no dry streaks remain.
- Bake Brownies: Spread the batter evenly in the prepared pan. Bake for 22 to 25 minutes, until the edges are set but the center still appears slightly underbaked. Allow brownies to cool completely in the pan.
- Chill Mixer Equipment: Place the bowl and wire whip attachment of a stand mixer or the bowl and beaters of a handheld mixer into the freezer to chill while preparing the mousse.
- Melt Chocolate and Marshmallows: In a medium saucepan over low heat, combine 4 ounces chopped semisweet chocolate, 1 cup mini marshmallows, and ¼ cup plus 1 tablespoon whole milk. Stir constantly until melted and smooth.
- Cool Chocolate Mixture: Remove from heat and let the chocolate mixture cool to room temperature to prevent deflating the whipped cream during mixing.
- Whip Cream: In a large mixing bowl, beat 1¼ cups cold heavy cream with an electric mixer until soft peaks form.
- Combine Mousse: Reduce mixer speed to low and gradually add the cooled chocolate mixture to the whipped cream. Increase speed to high and whip until stiff peaks form; be careful not to overwhip.
- Assemble: Spread the chocolate mousse evenly over the cooled brownie base using a silicone or offset spatula. Cover the pan and refrigerate for 2 hours to set.
- Serve: After chilling, use the parchment overhang to lift the brownies out of the pan and slice into 12 equal squares. Drizzle with chocolate syrup if desired. Keep refrigerated until serving.
Notes
- Do not overbeat the brownie batter or the eggs to maintain a fudgy texture.
- Cooling the chocolate mixture before folding into the whipped cream is crucial to preserve the mousse’s light texture.
- Use parchment paper with an overhang to easily remove the brownies for slicing.
- Chilling the mixing bowl and whisk helps achieve optimal whipped cream texture.
- Store brownies refrigerated and consume within 3 days for best freshness.
- Prep Time: 45 minutes
- Cook Time: 25 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
