In a large mixing bowl, whisk together the all-purpose flour, cocoa powder, baking powder, baking soda, and salt until well combined.

In another bowl, mix the granulated sugar, vegetable oil, buttermilk, eggs, red food coloring, vanilla extract, and white vinegar until smooth.

Gradually mix the wet ingredients into the dry ingredients until just combined.

Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, then evenly pour the red velvet cake batter into the pans.

Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean. Let them cool for about 10 minutes before transferring to wire racks to cool completely.

While the cake layers cool, beat the cream cheese and granulated sugar until smooth and creamy. Add the sour cream, eggs, and vanilla, mixing until fully combined.

Pour the cheesecake batter into a greased springform pan and spread it out evenly.

Bake the cheesecake at 350°F (175°C) for 45-50 minutes until set around the edges but slightly jiggly in the center.

Turn off the oven and leave the cheesecake inside for an additional 30 minutes to cool gradually.

Once cooled, assemble by placing one red velvet cake layer on a serving platter, followed by the cheesecake layer on top, and lastly the second cake layer.

Mix the softened unsalted butter with powdered sugar until smooth, then frost the top and sides of the assembled cake.

Chill the cheesecake in the refrigerator for at least 4 hours or overnight before serving.