Preheat your oven to 350°F (175°C). Crush Oreo cookies into fine crumbs and mix with melted butter. Press into the bottom of a 9-inch springform pan. Bake for 10 minutes and let cool.

In a mixing bowl, combine red velvet cake mix, cream cheese, granulated sugar, eggs, and vanilla extract. Beat until smooth, about 2-3 minutes. Pour over the cooled crust.

In another bowl, blend together cream cheese, sugar, eggs, and vanilla extract for vanilla layer until smooth. Pour over the red velvet layer in the pan.

Bake for about 60 minutes, until edges are set and the center has a slight jiggle. Cool in the oven with the door ajar for 1 hour.

Refrigerate the cheesecake for at least 7 hours or overnight.

For ganache, heat cream until simmering. Pour over chopped chocolate, stir until smooth, and cool slightly before pouring over cheesecake.

Remove the cheesecake from the pan, decorate with whipped cream and additional crushed Oreos. Slice and serve chilled.