Preheat oven to 350 degrees F. Grease a muffin tin liberally. Dip each Oreo into the brownie batter until they are thoroughly coated and make sure to let excess slip off before placing into muffin cup. Place each dipped Oreo into the greased muffin cup. Bake for around 12 minutes making sure not to over-bake... not even a little! Let cool and run a knife around the edge of each brownie and they should pop out! This makes at least 24 Oreo Brownies. Top each one with a little chocolate icing, the Reese's mini pieces and sprinkles. Enjoy!