Prepare Your Muffin Tin or Cupcake Tray:Line the muffin tin / cupcake tray with cupcake liners. Place one Oreo cookie at the bottom of each liner.
Make the Cheesecake Filling:In a bowl, mix the softened cream cheese and sugar until smooth.Add the egg, sour cream, and vanilla extract. Stir until everything is combined and creamy.
Fill and Bake:Spoon the cheesecake mixture evenly over the Oreo cookies in the cupcake liners. Fill each cup about 3/4 full.Bake at 325°F (160°C) for 18–20 minutes, or until the centers are set.Remove the muffin tin from the oven and let the cheesecakes cool in the tin for 15 minutes.
Chill:Transfer the cheesecakes to the fridge and chill for at least 2 hours (or overnight) to let them set completely.
Decorate and Serve:Just before serving, add a swirl of whipped cream on top of each cheesecake. Sprinkle with Oreo crumbs or place a mini Oreo on top for the perfect finish!