Line a muffin pan with cupcake liners. In a large bowl, combine Oreo cookie crumbs, granulated sugar and melted butter. Divide mixture evenly among the cupcake liners. Press the crumbs into the liners with your fingers or a spoon. Set aside while you prepare the cheesecake filling.

Preheat oven to 325°F. In bowl of stand mixer combine cream cheese and sweetened condensed milk, mixing on low speed until smooth. Add in egg, mix until combined. Add vanilla extract and chocolate, mix until smooth and combined.

Fold in mini chocolate chips. Divide the batter evenly among the prepared muffin pans, they should be mostly full.

Bake for about 20 minutes until center is set and doesn't jiggle when you shake the pan.

Cool cheesecake for 30 minutes on a wire rack. While the cheesecake cools, prepare the ganaches.

Place the dark chocolate in a small bowl. Place the white chocolate in a separate bowl. In a small saucepan, heat the heavy cream until it's just beginning to simmer. Pour 1/2 cup of the hot heavy cream over the dark chocolate, and the other 1/4 cup over the white chocolate. Let each sit for about 1 minute, and then whisk until smooth.

Spoon about 1 tablespoons of the dark chocolate ganache over the mini cheesecakes and shake until the chocolate covers the entire top of the cheesecake. Repeat for all the cheesecakes.

Place the white chocolate in a small Ziploc bag. Snip the corner of the bag to form a very small hole, and draw a spiral shape with the white chocolate on top of each of the mini cheesecakes. Using a toothpick, draw about 8 lines from the center of each cheesecake out to the edges to form the spiderweb shape.

Cover and refrigerate overnight before serving. Keep leftovers tightly wrapped in the refrigerator.