Step 1

Preheat oven to 350° F.

Step 2

In a medium sized bowl, combine brownie mix, egg, vegetable oil and milk. Beat until thoroughly mixed.

Step 3

Line a 9×13” pan with parchment paper or a baking mat. Pour brownie mixture over the baking mat and spread evenly. Set Oreo cookies in a line over top of the brownie mix.

Step 4

Soften butter in the microwave 10-15 seconds. Combine butter with both light brown sugar and granulated sugar. Mix until smooth and mixture becomes fluffy.

Step 5

Add egg and vanilla extract and beat until egg is thoroughly incorporated.

Step 6

In a separate bowl, combine flour, salt and baking soda. Slowly add flour mixture to dough batter while mixing at a low speed. Once all the flour has been added, increase speed to medium until dough forms.

Step 7

Chop Reese’s Peanut Butter Cups into small pieces. Add all but ¼ C into the cookie dough. Add peanut butter chips and fold into cookie dough.

Step 8

Take the cookie dough and drop chunks onto the top of the brownie mixture, gently pressing them down into brownie batter. Add remaining ¼ C Reese’s Peanut Butter Cups and press gently onto the top of the cookie dough.

Step 9

Bake for 23-25 minutes at 350°F. Remove from oven and allow to cool completely before cutting. Since I used a baking mat, I was able to completely remove the sheet of brookies from the pan before cutting.