Preheat oven to 325 degrees F. Place a large roasting pan on the lower third rack of the oven. Place a kettle of water on the stove to boil. Spray a 9-inch springform pan with nonstick spray and line the bottom with a round of parchment paper. Wrap a double layer of foil around the bottom and up the sides of the pan (you want to seal it, so the water from the water bath doesn't seep into the pan).
Use an electric mixer to mix the cream cheese- blend until it is nice and smooth and creamy in a large bowl. Mix in sugar and salt and blend for 2 minutes, scraping down the sides of the bowl as needed. Add eggs, one at a time, blending after each addition. Finally, mix in sour cream, whipping cream, and vanilla. Mix until smooth.
Pour the batter into the prepared pan. Set the pan into the roasting pan in the preheated oven. Carefully pour the hot water from your kettle into the roasting pan (it will fill the pan surrounding the cheesecake). Pour enough water so that there is about an inch of water coming up the foil along the cheesecake pan's sides.
Bake the cheesecake for 45 minutes. It should be set to the touch and not jiggly. Remove the cheesecake from the roasting pan and let it cool on a wire rack for at least an hour. When it has cooled, place the pan into the freezer and let the cheesecake freeze completely. This can be done in a couple of hours- or overnight.
MAKE THE RED VELVET CAKE LAYERS:
Preheat oven to 350 degrees F. Grease and flour two 9-inch round metal baking pans (or spray with nonstick baking spray with flour).
In a large bowl, whisk together flour, sugar, cocoa powder, baking soda, and salt. Add eggs, oil, buttermilk, food coloring, vanilla, and vinegar to the flour mixture. Using an electric mixer on medium-low speed, beat for 1 minute until blended. Scrape the sides and bottom of the bowl with a rubber spatula. Beat on high speed for 2 minutes.
Spread the batter evenly into the prepared pans, dividing equally. Bake 30 to 35 minutes or until a toothpick inserted in the center comes out with a few moist crumbs attached. Let cool in pans on a wire rack for 10 minutes. Run a knife around the pans' edge, then invert cakes onto a rack to cool completely.
MAKE THE CREAM CHEESE FROSTING:
In a large bowl, using an electric mixer on medium-high speed, beat powdered sugar, cream cheese, butter, and vanilla until it is smooth and creamy (do not overheat).
ASSEMBLE TO CAKE:
Place one cake layer into the center of a cake plate or platter. Remove the cheesecake from the freezer, take off the pan's sides, and slide a knife under the parchment to remove the cheesecake from the pan. Peel off the parchment.
Measure your cheesecake layer against the cake layers. If the cheesecake layer turns out to be a slightly larger round than your cake, move it to a cutting board and gently shave off some of the cheesecake's exteriors to get it to the same size as your cake layers.
Place the cheesecake layer on top of the first cake layer. Place the 2nd cake layer on top of the cheesecake.
FROST THE CAKE:
Apply a crumb coat layer to the cake- use a long, thin spatula to completely cover the cake with a thin and even layer of frosting. Be sure to wipe off your spatula each time you are about to dip it back into the bowl to get more frosting.
When your cake has a thin layer of frosting all over it, place it into the refrigerator for 30 minutes to "set" the frosting.
Once the first layer of frosting is set, apply the 2nd layer. Start by adding a large scoop of frosting onto the top of the cake. Use a long, thin spatula to spread the frosting evenly across the top and then spread it down the sides of the cake too.
Decorate with white chocolate shavings (see recipe notes below). Once the cake is finished, keep it refrigerated until ready to serve.
For making white chocolate shavings:
Purchase a hunk of white chocolate. Microwave the chocolate to soften it up slightly (15 to 30 seconds, depending on the size). Use a potato peeler to run down the side of the chocolate to create shards/shaves/curls of white chocolate. I like to shave it onto a paper plater and then use the plate to slide the chocolate onto the top of the cake.
If you are serving this cake at a party, it's perfectly okay to leave the cake at room temperature for an hour or so while serving. Otherwise, please keep it in the refrigerator. It also freezes perfectly! I made my cake one day and then placed it in the freezer and pulled it out the next day. It thaws quickly.