Preheat oven to 350 degrees.

Line a standard muffin tin with 12 baking cups. Place an Oreo cookie into the bottom of each cup. This will make the crust of your cheesecakes.

Combine cream cheese, egg, sugar, and vanilla in a mixing bowl and blend together with an electric mixer until smooth, about 3 minutes. Divide the mixture evenly between the 12 prepared cups.

Place 1/3 cup Nutella in a small, microwaveable bowl and heat for about 30 seconds. Place a small scoop into the center of each cheesecake and swirl with a toothpick.

Bake in the preheated oven for about 25 minutes, or until cheesecakes are set. Remove from oven and cool on a wire rack for 30 minutes. Transfer to the refrigerator and chill for at least 3-4 hours.

When ready to serve, crumble the remaining Oreo cookies and sprinkle over the top of the cheesecakes. Place 4 TB Nutella into the bottom corner of a small ziploc bag. Heat in the microwave for 20-30 seconds until warmed and easily spreadable. Cut a VERY small tip from the corner of the bag, and drizzle Nutella over the top of each cheesecake. Serve and enjoy!