Preheat oven to 325 degrees. Line an 8x8" or 9x9" pan with parchment paper, set aside.

Place butter, cocoa and sugar in a large microwave-safe bowl and microwave for about 1 minute and 30 seconds, or until butter is melted. Mix everything together until smooth. Add in eggs and vanilla and mix until smooth. Pour in the flour and mix until just combined. Gently fold in chocolate chips and chopped oreos until evenly distributed. The batter will be very thick. Pour batter in prepared pan and spread into an even layer. Bake for 25-28 minutes or until a toothpick inserted in the center comes out mostly clean with a little bit of batter on the end. (This will ensure your brownies will be fudgy when they set!) Allow brownies to cool in pan for 10 minutes before transferring them to a wire rack to finish cooling completely before frosting.

While brownies are cooling, prepare frosting. Cream together the cream cheese and butter until completely smooth with no lumps. Add in the vanilla. Incorporate confectioner's sugar one cup at a time until light and fluffy. If you'd like a thinner frosting, add some cream or milk 1 teaspoon at a time to loosen it up. Fold in crushed oreos until evenly distributed throughout frosting.

Once brownies are completely cool, spread a thick layer of frosting on top. Cut into bars and serve.

Cookies and cream frosted brownies will stay fresh for up to 5 days stored in an airtight container at room temperature.