Prepare the Brownie Base:

• In a mixing bowl, whisk together the melted butter, sugar, and cocoa powder until smooth.
• Add eggs one at a time, whisking after each addition, then stir in vanilla extract.
• Gently fold in flour and salt until just combined.
• Pour the brownie batter evenly into a greased or parchment-lined 8×8-inch or 9×9-inch baking pan.

Make the Cookie Dough:

• In a separate bowl, cream the softened butter with brown sugar and granulated sugar until light and fluffy.
• Mix in the egg and vanilla extract until smooth.
• Fold in flour, baking powder, and salt until just combined, then stir in chocolate chips.
• If the dough is too soft, chill it in the refrigerator for a few minutes.

Assemble the Brookies:

• Spoon the cookie dough in small portions over the brownie batter.
• Lightly press the dough down without mixing the layers together.

Bake to Perfection:

• Preheat the oven to 350°F (175°C).
• Bake for 30-35 minutes, until the cookie layer is golden-brown and a toothpick inserted into the brownie comes out with moist crumbs.
• Let the brookies cool completely in the pan before slicing.

Serve and Enjoy:

• Slice into squares and serve as is or with a scoop of ice cream for an extra treat!