Make the Cheesecake
Preheat oven to 350°F (175°C). Spray a 9-inch springform pan with nonstick cooking spray and line the bottom with parchment paper.
Beat cream cheese, sugar, flour, and salt until smooth and creamy, about 3 minutes.
Add heavy cream and vanilla; mix until combined.
Add eggs one at a time, mixing briefly after each addition.
Pour batter into the prepared pan and spread evenly.
Bake for 40–55 minutes or until set and no longer jiggles.
Cool on a wire rack for 1 hour, then freeze for at least 3 hours or overnight.
Make the Red Velvet Cake
Preheat oven to 350°F (175°C). Grease and line two 9-inch cake pans with parchment paper.
Cream butter and sugar until light and fluffy.
Add eggs one at a time, beating well after each addition.
Mix cocoa powder, vanilla, and red food coloring into a paste and blend into the batter.
Alternate adding buttermilk and flour, mixing until incorporated.
Add salt, baking soda, and vinegar; beat until smooth.
Divide batter evenly between pans.
Bake for approximately 30 minutes or until a toothpick inserted into the center comes out clean.
Cool completely before assembling.
Make the Frosting
Beat butter, powdered sugar, vanilla, and salt until smooth.
Add cream cheese one piece at a time and continue beating until creamy and fluffy.
Assemble the Cake
Level cake layers if necessary.
Place one cake layer on a serving plate.
Remove cheesecake from the freezer and trim edges if needed to match the cake size.
Place cheesecake on top of the first cake layer.
Add the second cake layer upside down.
Apply a thin crumb coat of frosting and refrigerate for 30 minutes.
Frost the entire cake with the remaining frosting and decorate as desired.
Refrigerate until ready to serve. Let stand at room temperature for 20 minutes before slicing.