• Preheat the oven to 350 ºF. Grease a 9x13-inch baking pan with shortening; set aside.

For the cookie dough:

• Whisk together the flour, baking soda, and baking powder in a medium bowl. Beat the butter and both sugars on medium-high speed in the bowl of a stand mixer fitted with a paddle attachment (or in a large bowl if using a handheld mixer) until light and fluffy, about 4 minutes. Add the egg and beat until incorporated. Beat in the vanilla. Scrape down the side of the bowl as needed. Reduce the speed to medium, add the flour mixture, and beat until just incorporated. Stir in the chocolate chips. Cover with plastic wrap and chill in the freezer while you make the brownie batter.

For the brownie batter:

• Place the butter in a medium microwave-safe bowl and melt it in the microwave, for about 1 minute. Alternatively, you can melt the butter and chocolate in a medium saucepan over medium heat, stirring frequently. Add the chocolate, and whisk until the chocolate is completely melted. Let cool slightly.
• Whisk in the sugars, salt, and vanilla. Whisk in the eggs until just combined. Add the flour mixture, and stir to combine. Pour the batter into the prepared pan, and spread evenly with a spatula.
• Remove the cookie dough from the freezer and dollop small spoonfuls of the cookie dough evenly over the brownie batter. Bake for 20 to 25 minutes, rotating the baking sheet halfway through cooking time. Let stand for 15-20 minutes before serving.
• To serve, lift the brookies out of the pan using the parchment overhang and transfer them to a cutting board. Pull the parchment away from the edges. Using a sharp knife, cut the brookies into 2-in squares directly on the parchment. Enjoy!😋🥛🍪