Preparation

• Preheat the oven to 350°F. Line a 9×13-inch baking dish with parchment paper, leaving some overhang for easy removal of the brownies.
• In a large bowl whisk flour, cornstarch, cocoa, baking powder, and salt. Set aside.
• To the bowl of a stand mixer fitted with the paddle attachment, add the eggs, sugar, butter, and vanilla. Beat on medium speed until light and fluffy.
• With the mixer off, add the flour mixture. Turn the mixer on low and mix until the ingredients are well combined.
• Pour brownies into the prepared baking dish and bake for 30-35 minutes, or until done.
• Let the brownies cool at room temperature.
• In a microwave-safe bowl, heat ½ cup of the heavy cream for 50 seconds.
• Add the chocolate chips to the cream and stir until the chocolate has melted. Set aside to cool.
• Pour the remaining 1 cup of heavy cream into a medium bowl. Using a hand-held or stand mixer, beat until soft peaks form.
• Continue whipping the cream until stiff peaks form.
• Fold the cooled chocolate mixture into the whipped cream until combined.
• Pour the mousse over the cooled brownies and spread it into an even layer. Garnish with chocolate curls (optional).
• Refrigerate for 2 hours (up to overnight) before serving.