2In one bowl, combine all cookie wet ingredients and mix until smooth.
3In a separate bowl, combine all cookie dry ingredients, then mix wet and dry together.
4Add mix-ins to the cookie batter.
5In another bowl, combine all brownie wet ingredients and mix.
6In a separate bowl, mix all brownie dry ingredients, then combine wet and dry.
7Line a cookie sheet with parchment paper and lightly coat with cooking spray.
8Spread the brownie batter evenly.
9Drop spoonfuls of the cookie dough on top of the brownie layer.
10Add chocolate chips or toppings (optional).
11Bake at 350°F for about 15-20 minutes, or until edges are set but center is slightly soft (should be slightly underdone looking but toothpick will come out clean).
12Remove from oven and allow to cool completely so it firms up.
13Once cooled, slice into 88 pieces or desired size. Then enjoy!