Preheat the Oven
Preheat your oven to 325°F (163°C). Grease a 9-inch springform pan and line the bottom with parchment paper for easy removal.
Make the Oreo Crust
In a food processor or plastic bag, crush the Oreos into fine crumbs. Combine the crushed Oreos with melted butter and mix until the mixture is evenly moistened. Press the mixture into the bottom of the springform pan, creating a firm, even layer. Bake the crust for 10 minutes, then remove from the oven and set aside to cool.
Prepare the Red Velvet Cheesecake Filling
In a large mixing bowl, beat the cream cheese until smooth using an electric mixer. Add the granulated sugar and continue to beat until combined. Add the sour cream, eggs, vanilla extract, cocoa powder, and red food coloring, mixing until smooth and well combined.
Bake the Cheesecake
Pour the cheesecake batter into the cooled Oreo crust and spread it out evenly. Bake in the preheated oven for 55-60 minutes or until the center is just set and a toothpick inserted comes out clean. The cheesecake will still have a slight wobble when done. Turn off the oven and allow the cheesecake to cool in the oven for 1 hour with the door slightly ajar. Afterward, remove from the oven and let it cool to room temperature. Refrigerate for at least 4 hours, or overnight for best results.
Make the Chocolate Ganache
In a small saucepan, heat the heavy cream over medium heat until it begins to simmer. Remove from heat and add the chopped semisweet chocolate. Stir until the chocolate is completely melted and smooth. Let the ganache cool slightly before pouring it over the chilled cheesecake.
Top the Cheesecake
Once the cheesecake has cooled and set, pour the chocolate ganache over the top, spreading it evenly with a spatula. Allow the ganache to set for about 30 minutes to firm up.