Step 1

Preheat oven to 350ºF. Prepare an 8x8 baking pan by lightly spraying it with nonstick cooking spray and/or lining it with parchment paper.

Step 2

Whisk together the butter and sugar until combined. Mix in the vanilla and the eggs, one at a time.

Step 3

Mix in the baking soda and salt.

Step 4

Add the flour and cocoa powder. Mix until batter forms.

Step 5

Fold in the chocolate chunks. Pour batter into prepared pan.

Step 6

Combine flour, baking soda and salt in small bowl.

Step 7

Beat butter, granulated sugar, brown sugar and vanilla extract in large mixer bowl until creamy.

Step 8

Add eggs, one at a time, beating well after each addition. Gradually beat in flour mixture. Stir in chocolate chips.

Step 9

Scoop tablespoons of cookie dough and flatten slightly with your fingers.

Step 10

Layer the dough on top of the brownie batter. You'll only need about half of the dough, so cover and refrigerate the remaining dough to use for cookies later!

Step 11

Bake for 30-35 minutes. The edges should be starting to pull away from the pan and a toothpick inserted should come out mostly clean.

Step 12

Let cool before cutting.