Line a 9×13 pan with foil and spray with cooking spray. Set aside.

In a large pot, melt the butter over low heat. Once the butter is melted start to whisk constantly. First the butter will begin to foam, then after a couple of minutes it will begin to brown on the bottom of the saucepan.

Once the butter is browned and toasted, add the marshmallows and cook on low, stirring constantly, until mostly melted, a few small lumps here and there are ok.

Remove from the heat and stir in the vanilla and salt.

Add the cereal and oreos and stir until well-combined.

Scrape the mixture into the prepared pan and using lightly greased or barely wet hands, lightly press the mixture into the pan. Let cool for at least 20 minutes before slicing. Enjoy!