1. Preheat the oven to 350 degrees.  2. Crush half of Oreos 3. Dip half of other Oreos in melted butter.  4. Beat together the cream cheese, sugar, sour cream, and vanilla. 5. Add the eggs. 6. Fold in half of crushed cookies. 7. Spoon the batter in cupcake liner 2/3 full. Sprinkle the remaining crushed cookies over the top of each mini cheesecake. 8. Bake in the preheated oven for 30 to 35 minutes. 9. Allow the cheesecakes to cool. Transfer them to the refrigerator to chill for at least one hour. 10. Tip with whipped cream if desired.