• For the Cheesecake Layer
• Place a 9x13 (or similar size) pan filled with one inch of water on a rack in the bottom ⅔ of the oven. (Just under the rack where your cheesecake layer will bake)
• Preheat oven to 300 degrees F
• Line the bottom of a 9 inch spring form pan with a circle of parchment paper.
• In a mixing bowl, mix softened cream cheese until smooth.
• Mixing at low speed, add sugar, salt, flour.
• Add vanilla extract and sour cream. Mix at low speed until smooth and incorporated. Add eggs one at a time. Mix until well combined.
• Pour the cheesecake batter into springform pan lined with parchment and place on a rack just above the pan of water.
• Bake for 45 minutes. The cheesecake should be set at this point- it may jiggle slightly.
• Turn off the oven and leave cheesecake inside for 30 more minutes with the oven door slightly open. (This helps the cake to cool without cracking.)
• Then, allow the cheesecake to cool on the countertop. Then, place foil on the pan and chill in the freezer for 2-3 hours. If you are not in a hurry, you can refrigerate the cake for 5-6 hours or overnight.

For the Red Velvet Cake Layers

• Preheat the oven to 350 degrees, grease and flour two 9×2 inch round pans. I lined the bottom of my pans with parchment paper also.
• In a medium bowl, whisk the flour, baking powder, baking soda, salt, and cocoa powder for 30 seconds. Set aside
• In another bowl, add the buttermilk, white vinegar, vegetable oil, vanilla extract, and red food coloring.  Set aside..
• In the bowl of your mixer, add the butter and mix at medium speed until smooth. Gradually add the sugar and continue to mix on medium speed for 3 to 5 minutes until lightened in color and fluffy. Add the eggs one at a time mixing until the yellow of the yolk is blended.
• With the mixer on low speed, alternately add the flour mixture and buttermilk mixture, beginning and ending with the dry ingredients (3 additions of dry ingredients and 2 of liquid). After the last addition, mix just until blended.
• Divide batter between the two prepared 9 inch cake pans.
• Bake at 350 degrees for 25-30 minutes or until a toothpick inserted in the center comes out clean or with just few crumbs attached. They layers should spring back when lightly touched in the center. Let cool 10 minutes and turn out.

For the Cream Cheese Frosting

• Cut the butter into slices and add to the bowl of your mixer. Mix on low to medium speed until the butter is softened and smooth.
• Cut the softened cheese into pieces and add to the butter, beating at low to medium speed until incorporated.
• Add the vanilla. Gradually add the powdered sugar, mixing on low speed until blended. Cover the bowl with a towel if needed to keep down the cloud of powdered sugar.
• Increase mixing speed to medium and mix until fluffy. Don't over mix or it will become too soft. If it becomes too soft, just refrigerate a short while to firm it up a bit.
• This frosting will pipe best if used while still chilled. You can make it in advance, refrigerate and when ready to use let it soften slightly (do not microwave) and remix.

Assembling the Cake

• Place the first cooled or chilled red velvet cake layer on the cake plate or pedestal. Spread with a thin layer of cream cheese frosting.
• For the cheesecake layer, run a thin knife (I like to heat it with hot water) between the cake and side of the springform cake pan to help prevent sticking.
• Release the sides of the springform pan.
• Carefully, place the cheesecake upside down onto the first cake layer. remove the bottom of the cake pan. If it sticks at all, use a thin, hot knife to slide between the pan and the cake to release.
• Remove the parchment if you haven't already! ;0) -
• Spread the cheesecake layer with a thin layer of frosting. Top with the top red velvet cake layer.
• *If your cheesecake layer is slightly wider than your cake layers, just trim away the excess with a hot knife.
• Frost the cake as usual. If at any time the frosting becomes too soft, or the layers are sliding, just pop it in the freezer for 15 minutes to firm things up. (And you can refrigerate the bowl of frosting also as needed.)
• This cake should be refrigerated.