Allow plenty of time to make fillings, and immediately assemble stacks. You can chill the assembled stacks up to 24 hours ahead of time.
- Vegetable cooking spray
- 3/4 cup butter
- 1 (4-oz.) bittersweet dark chocolate baking bar, chopped
- 1 1/2 cups sugar
- 1 teaspoon vanilla extract
- 4 large eggs
- 1 cup all-purpose flour
- 1/4 teaspoon baking powder
- 1/4 teaspoon table salt
Milk Chocolate Mousse
- 1/2 (12-oz.) package milk chocolate morsels (1 cup)
- 1/4 cup creamy peanut butter
- 1 cup heavy cream
White Chocolate Mousse
- 1 cup white chocolate morsels
- 1 1/4 cups heavy cream, divided
- 8 large paper clips
- Heavy-duty aluminum foil
- Garnish: shaved chocolate
- Prepare Brownies: Preheat oven to 350°.
- Line bottom and sides of a 13- x 9-inch pan with aluminum foil, allowing 2 to 3 inches to extend over sides; lightly grease foil with cooking spray.
- Microwave butter and chopped bittersweet chocolate in a large microwave-safe bowl at HIGH 1 1/2 to 2 minutes or just until melted and smooth, stirring every 30 seconds.
- Whisk in sugar and vanilla.
- Add eggs, 1 at a time, whisking just until blended after each addition.
- Stir together flour, baking powder, and salt in a small bowl.
- Whisk flour mixture into chocolate mixture until blended. Pour mixture into prepared pan.
- Bake at 350° for 18 to 20 minutes or until a wooden pick inserted in center comes out with a few moist crumbs.
- Cool completely on a wire rack (about 1 hour).
- Lift brownies from pan, using foil sides as handles.
- Cut 8 circles, using a 3-inch round cutter. Reserve scraps for another use.
- Prepare Milk Chocolate Mousse: Microwave milk chocolate morsels and peanut butter in a small microwave-safe glass bowl at MEDIUM (50% power) 1 1/2 to 2 minutes or until melted and smooth, stirring every 30 seconds.
- Cool 5 minutes.
- Beat 1 cup heavy cream at medium speed with an electric mixer until soft peaks form; fold cream into milk chocolate mixture.
- Chill while making White Chocolate Mousse.
- Prepare White Chocolate Mousse: Microwave white chocolate morsels and 1/4 cup cream in a small microwave-safe glass bowl at MEDIUM (50% power) 1 1/2 to 2 minutes or until melted and smooth, stirring every 30 seconds.
- Cool 5 minutes.
- Beat remaining 1 cup cream at medium speed with an electric mixer until soft peaks form; fold into white chocolate mixture. Chill while preparing foil molds for Step 19.
- Assemble Stacks: Wash and dry paper clips. Cut heavy-duty aluminum foil into 8 (6- x 10-inch) pieces.
- Fold each piece in half to form a 3- x 10-inch strip.
- Wrap each strip around a 3-inch-diameter can. (This helps create a smooth curve.)
- Wrap 1 curved foil strip around each brownie; secure with a large paper clip.
- Immediately spoon Milk Chocolate Mousse into a zip-top plastic freezer bag. (Do not seal.) Snip 1 corner of bag to make a small hole (about 1/2 inch). Pipe mousse onto brownies, dividing mixture evenly. Use a small spoon to level gently.
- Repeat procedure with White Chocolate Mousse.
- Chill 2 hours; remove foil to serve.