How to Make It
Prepare the brownies: Preheat oven to 350°F. Line bottom and sides of a jelly-roll pan with parchment paper; coat parchment with cooking spray. Melt chocolate chips, butter, and unsweetened chocolate in a double boiler, stirring often, until melted and incorporated. Cool slightly. Whisk together sugar, eggs, and vanilla in a large bowl. Add cooled chocolate mixture to sugar mixture. Sift together flour, cocoa, and baking powder. Gently stir flour mixture into chocolate mixture just until incorporated. Spread batter in prepared pan. Bake in preheated oven until a toothpick comes out with moist crumbs, 14 to 16 minutes. Cool completely in pan on a wire rack.
Invert a 6-inch (2 1/2-cup) bowl onto brownies. Cut a circle around bowl. Cut a second 3-inch circle from brownies. Line the 6-inch bowl with plastic wrap, allowing 6 inches of plastic wrap to extend over sides of bowl.
Microwave ice cream on HIGH until softened, 5 to 10 seconds. Spread 3/4 cup of the ice cream in the bottom of prepared bowl. Top with small brownie circle; press down gently. Spread 1 1/4 cups of the ice cream over small brownie circle. Top with large brownie circle; press down gently. Fold excess plastic wrap over brownie to cover. Freeze 4 hours or overnight. Reserve leftover brownie pieces for another use.
When ready to serve, invert ice cream dome onto a plate, and remove bowl and plastic wrap. Let stand in refrigerator 15 minutes.
Prepare the meringue: Beat egg whites with an electric mixer on medium speed until foamy, about 1 minute. Increase speed to medium-high; gradually add sugar, 1 tablespoon at a time, until soft peaks form, 1 to 2 minutes. Spread meringue over ice cream dome with a spoon or offset spatula to make fun peaks. Lightly char with a blowtorch. Cut into 4 wedges.