Preheat your oven to 350°F (175°C) and prepare the pans by lining them with parchment paper and spritzing with non-stick spray.

In a mixing bowl, whisk together the all-purpose flour, cocoa powder, and a pinch of salt.

Cream together the softened butter and granulated sugar until light and fluffy, then add sour cream, vegetable oil, vanilla extract, and eggs, mixing until well-combined.

Gradually add the dry mixture to the creamed mixture, alternating with the buttermilk, mixing until just combined, then add baking soda and vinegar.

Divide the batter between the prepared pans and bake for 18-20 minutes, or until a toothpick comes out clean. Let the layers cool on wire racks.

To make the cheesecake filling, crush the Oreos and beat cream cheese until smooth, then mix in cornstarch and combined Oreos.

Fold the crushed Oreo crumbs into the cheesecake mixture and pour over the cooled red velvet layers in the springform pan.

Bake the cheesecake in a water bath at 300°F (150°C) for about 90 minutes, until the edges are set with a slight jiggle in the center.

Gradually cool the cheesecake in the oven with the door slightly open for an hour, then refrigerate overnight.

Make the ganache by heating heavy cream and pouring over dark chocolate chips; stir until smooth.

Pour the ganache over the chilled cheesecake, allowing it to drape down the edges, then decorate and serve chilled.