Preheat oven to 350 and line a square baking pan with parchment paper.
Start with the cookie dough. On the stovetop melt the butter and set aside to cool. Add the flour, baking soda and salt to a bowl and whisk.
In another bowl, add the sugars and one egg. Mix this together until smooth. Add the vanilla extract. Slowly add the flour mixture 1 cup at a time until fully combined. Last, slowly fold in your chocolate chips and oreos (1 sleeve of oreos crushed). Set aside and start the brownie batter.
In a bowl, whisk the sugar, egg, and vanilla together until light and fluffy.
On the stove, melt the butter and chocolate chips together until smooth. Fold in the cocoa powder, flour, and pinch of salt. Mix until everything is fully combined. Add the stove mixture to your egg and sugar mixture you have in a bowl. Mix together and add the brownie mixture to your square parchment paper lined baking pan. Use a spoon to spread it around. Add scoops of cookie dough on top of the brownie mixture.
Bake for 25-27 minutes.
Let cool in the pan for 5 minutes and cut into 9 pieces.
