Preheat your oven to 350℉.
In a medium pot, melt the butter and whisk in the sugar until well combined.
Turn off the heat and add the eggs one at a time, whisking constantly.
Add in the vanilla and chocolate chips, whisking again until melted.
Fold in the salt, all purpose flour, and cocoa powder just until combined.
Fold in the white chocolate chips and set aside.
Line a 9×9 pan and layer the Oreos along the bottom.
Top with the brownie batter and spread into an even layer over the cookies.
Bake for 30 minutes.
Cool for an additional 30 minutes before slicing!