Prepare the crust: In a food processor, crush the Oreo cookies until fine crumbs form. Add the melted butter and pulse until the mixture is combined. Spoon about 1 tablespoon of the Oreo mixture into each cupcake liner and press down gently to form a solid crust. Set aside in the freezer to chill while you prepare the filling.

1. Make the cheesecake filling: In a large bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Add the powdered sugar, vanilla extract, sour cream, cocoa powder, and red velvet cake mix (and food coloring if desired) to the cream cheese mixture. Beat until well combined. In a separate bowl, beat the heavy whipping cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture until smooth and fluffy.
2. Assemble the mini cheesecakes: Spoon the cheesecake mixture into each cupcake liner, filling it to the top. Smooth the top with a spatula. Place the mini cheesecakes back in the fridge and allow them to chill for at least 4 hours, or overnight for best results.
3. Serve: Once chilled and set, remove the cheesecakes from the cupcake liners and serve. Garnish with a whole Oreo cookie on top or some whipped cream if desired.