Preheat your oven to 350°F (175°C) and grease a 9x9-inch baking pan.

Prepare the cookie dough by letting it sit at room temperature for about 10 minutes.

In a medium bowl, whisk together the dry ingredients: flour, baking powder, salt, and cocoa powder. In a large bowl, combine the granulated sugar, brown sugar, and melted butter. Mix until smooth, then add the eggs and vanilla extract, stirring until well combined. Gradually add the dry mixture to the wet ingredients, mixing until just combined. Fold in the chocolate chips.

Spread half of the brownie batter evenly in the bottom of the prepared pan. Layer the cookie dough over the brownie batter and press it down gently. Spread the remaining brownie batter over the cookie layer.

Bake for 30-35 minutes, checking for doneness with a toothpick.

Let the brownies cool for at least 15 minutes before cutting into squares.