Preheat the oven to 350 degrees F. Place 12 cupcake liners in a muffin tin, and then place one Oreo cookie in the bottom of each cup. Set aside.
In a medium mixing bowl, beat the cream cheese with a hand mixer until smooth, about 2-3 minutes. Mix in the sugar and vanilla extract until smooth. Mix in the eggs, one at a time. Add the Oreo crumbs and larger Oreo pieces to the bowl and mix in with a rubber spatula.
Place a heaping 2 tablespoons of cheesecake batter into each muffin tin cup. (see note)
Bake for 14-16 minutes or until the center of the cheesecake is only slightly jiggly. (Do not overbake.)
Remove from the oven. Let the cheesecakes rest in the pan for about 10 minutes. Then transfer them to a wire rack to cool to room temperature, about 1 hour.
Once cooled, place the cheesecakes in the fridge for at least 2 hours to chill. Top with whipped cream or Cool Whip and an oreo cookie for garnish.
Notes
If you don't plan to add whipped cream on top of the cheesecakes, I recommend sprinkling some more Oreo crumbs and small pieces on top before baking.