Step 1

First, preheat your oven to 350 degrees Fahrenheit (175 degrees Celsius) and line a 9 by 9 inch baking pan with parchment paper.

Step 2

Start by making the brownie batter.  In a microwave-safe bowl, melt the butter.  Let it cool slightly.

Step 3

In a large mixing bowl, combine the melted butter, granulated sugar, eggs, and vanilla extract.  Mix until well combined.

Step 4

Then, add the cocoa powder, flour, salt, and baking powder to the bowl.  Stir until all the ingredients are fully incorporated and the batter is smooth.

Step 5

Spread the brownie batter evenly into the prepared baking pan.  Smooth the top with a spatula.  Set aside.

Step 6

Next, make the cookie dough.  In a separate mixing bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy.

Step 7

Add the egg and vanilla extract to the bowl.  Mix until well combined.

Step 8

In another bowl, whisk together the flour, baking soda, and salt.  Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Step 9

Fold in the chocolate chips.

Step 10

Drop spoonfuls of the cookie dough onto the brownie batter in the baking pan.  Use a spatula or your fingers to gently press the cookie dough down into the brownie batter.

Step 11

Bake in the preheated oven for about 25 to 30 minutes or until a toothpick inserted into the center comes out with a few moist crumbs.  The brownie and cookie layers should be set.

Step 12

Remove the brookies from the oven.  Let them cool in the pan on a wire rack.

Step 13

Once cooled, lift the brookies out of the pan using the parchment paper as handles.  Finally, cut into squares and serve.