• Line a square 8x8 baking pan with parchment paper to hang over two sides, and gently grease the other two sides. Then preheat the oven to 350°F/180°C.

For the Cookie Dough

• In a large bowl, cream the butter and light brown sugar for 2 minutes.
  1/3 cup butter, 1/2 cup brown sugar
• Add in egg yolk and vanilla and continue whisking.
  1 egg yolk, 1 tbsp vanilla
• Fold in the flour, baking soda, salt. Lastly add in the chopped Oreos. Set aside.
  1 cup all-purpose flour, 1/4 tsp salt, 1/2 tsp baking soda, 5 Oreos

For the Brownie Batter

• Melt the butter and chocolate chips together until smooth. Set aside to cool for 10 minutes.
  1/4 cup butter, 1/3 cup semi-sweet chocolate chips
• Once slightly cooled, whisk in white sugar, then the egg and vanilla. Make sure it's not to hot, we don't want to cook our egg!
  1/3 cup white sugar, 1 egg, 1 tbsp vanilla
• Fold in the flour and cocoa powder until just combined.
  1/4 cup all-purpose flour, 1/4 cup unsweetened cocoa powder
• Scoop the cookie dough balls into the prepared pan. Using the same cookie scoop, add the brownie batter in between the cookie dough balls.
• The entire bottom of the pan should be covered by cookie dough and brownie batter. Make sure it is all the same height, if not gently press the cookie dough balls down to meet the brownie height. Bake in the preheated oven for 25-27 minutes.
• You'll know the brookies are ready when a toothpick comes out with crumbs. When ready, remove from oven. Allow to cool, slice, and enjoy!