Preheat oven to 350°F. Line two large baking sheets with parchment paper and set aside.

In a large mixing bowl, add the granulated sugar, light brown sugar, large eggs, and vanilla extract. Beat on medium speed, using a handheld mixer, for 6-7 minutes or until the mixture is thick, fluffy, and pale in color. This step is essential for achieving the crackly top.

Add the melted and cooled butter and chocolate. Beat again on medium speed just until fully incorporated and no streaks of chocolate remain.

Whisk together the all-purpose flour, unsweetened cocoa powder, baking powder, and salt in a separate bowl. Be sure to break apart any lumps of cocoa powder.

Add the dry ingredients to the bowl of the wet ingredients and mix on low speed just until fully combined.

Fold the semi-sweet chocolate chips into the brownie cookie batter.

Using a 1½ tablespoon cookie scoop, scoop out 12 brownie cookies onto each of the prepared baking sheets.

Bake for 8-10 minutes or until the tops are crackly and the center is set. Do not overbake, or your cookies will become tough and lose their chewy, fudgy interior texture.

Allow the cookies to cool on the baking sheets for 10 minutes before transferring them to a wire rack to cool completely. You can sprinkle a pinch of the flaked sea salt onto the tops of the warm cookies if desired.