Preheat oven to 350, line a baking pan with parchment paper. Cookie dough layer: Cream butter and sugars together, then add the vanilla and eggs. Next add the flour, salt, baking soda, baking powder and mix until incorporated. Lastly add the chocolate chips then press the cookie dough into bottom of pan. Add a layer of non-overlapping oreos. Mix up brownie mix according to pkg. directions. Spread the brownie batter over the oreos and bake. Check on them at 30 min. but may take 50. min. Allow to cool before cutting. Top with chocolate sauce.