Start by preparing the cheesecake layer since it needs time to chill. Preheat your oven to 325°F (163°C). In a large mixing bowl, beat the softened cream cheese on medium speed until smooth and creamy. Add the granulated sugar and continue to mix until well combined. One at a time, add the eggs, mixing on low speed after each addition. Blend in the vanilla extract and sour cream until the mixture is smooth and lump-free.

Pour the cheesecake batter into a greased and parchment-lined springform pan. Tap the pan gently on the counter to release any air bubbles. Bake for 45 to 50 minutes, or until the center is just set and slightly jiggly. Turn the oven off and crack the door open, allowing the cheesecake to cool inside for 1 hour. Then remove and chill in the fridge for at least 4 hours, or preferably overnight.

While the cheesecake is chilling, prepare the red velvet cake layers. Preheat your oven to 350°F (177°C). In a large bowl, whisk together the flour, sugar, baking soda, salt, and cocoa powder. In another bowl, mix the oil, buttermilk, eggs, red food coloring, vanilla, and vinegar until smooth. Combine the wet and dry ingredients, mixing until fully incorporated.

Divide the batter evenly between two greased and parchment-lined 9-inch round cake pans. Bake for 30–32 minutes or until a toothpick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.

Once all layers are cool and the cheesecake has set, it’s time to assemble. Place one red velvet cake layer on a serving plate or cake stand. Carefully place the cheesecake layer on top. If necessary, use a serrated knife to level the tops of your cakes. Add the second red velvet layer over the cheesecake and press gently.

In a large bowl, beat together the cream cheese and butter for the frosting until light and fluffy. Gradually add the powdered sugar, vanilla extract, and salt, mixing until smooth. Frost the top and sides of the cake with an offset spatula, smoothing as desired. For a clean look, refrigerate the frosted cake for at least an hour before slicing.