Place cupcake liners into muffin tins. Place one Oreo cookie on the bottom of each cupcake liner.
In a mixer, beat the cream cheese, add the sugar and mix until smooth. Add eggs one at a time, beating after each egg. Mix until smooth. Spoon batter over each Oreo cookie in the cupcake liners until they are each 3/4 full. Bake at 350 degrees for 15-20 minutes or until the center of each cupcake is almost set. Remove from oven, cool completely and refrigerate overnight before serving.
They can be drizzled with melted chocolate or Cool Whip if desired. Keep refrigerated.