Pre-heat the oven to 350 degrees F.
Line the bottom of a 9x9 baking pan with tin foil and then spray the tin foil with a layer of baking spray.
Layer the cookie dough on the bottom of a 9x9 baking pan, pressing down to form the bottom of the slutty brownies.
Layer as many oreos that will fit on top of the cookie dough. No need to overlap. One single layer will do.
Pour the brownie batter on top of the oreo layer and make sure it's evenly layers on top.
Bake for 30-40 minutes. Test with a knife to see if the center is done. If the knife comes out clean, let the brownies rest for at least 2 hours before serving. If the knife comes out with batter still on it, allow the brownies to bake about 5 minutes more. Slice and serve.