Preheat the oven to 350°F. Grease a 9-inch springform pan and line the bottom with parchment if desired.
Prepare the red velvet cake batter according to the package directions, using the eggs, oil, and water listed on the box.
Pour the cake batter into the prepared springform pan and smooth the top with a spatula.
Bake the cake layer at 350°F for 30 minutes, or until a toothpick inserted in the center comes out clean.
Remove the pan from the oven and let the cake cool completely in the pan on a wire rack.
If the cake has domed, use a serrated knife to gently level the top so the cheesecake layer sits flat.
Place the cooled cake in the refrigerator and chill until firm, about 45 minutes to 1 hour.
Reduce the oven temperature to 325°F.
In a large mixing bowl, beat the softened cream cheese and granulated sugar with a mixer on medium speed until smooth and creamy, about 2 minutes.
Add the 2 eggs one at a time, mixing on low speed after each addition just until combined and scraping the bowl as needed.
Add the sour cream, flour, 1 teaspoon vanilla bean paste, and salt, then mix on low speed until the batter looks smooth and uniform.
Remove the chilled cake from the refrigerator and line the inner sides of the springform pan with a strip of parchment paper that rises slightly above the rim.
Pour the cheesecake batter gently over the cake layer and smooth the top with a spatula.
Tap the pan firmly on the counter a few times to release any large air bubbles in the cheesecake batter.
Place the pan on a baking sheet and bake at 325°F for 55 minutes, or until the outer edges are set and the center jiggles slightly when you gently shake the pan.
Turn off the oven, crack the oven door open slightly, and let the cheesecake cool inside for 30 minutes.
Remove the cheesecake from the oven and cool completely at room temperature on a wire rack.
Cover the cooled cheesecake and refrigerate for at least 4 hours, or until very firm, or freeze for about 1 hour to speed up firming before topping.
About 15 minutes before serving, place a large metal mixing bowl and beaters in the refrigerator to chill.
Add the cold heavy whipping cream to the chilled bowl along with the powdered sugar and 2 teaspoons vanilla bean paste.
Beat on medium high speed until soft peaks form and the cream holds its shape but still looks smooth and billowy.
Release and remove the sides of the springform pan, then peel away the parchment from the edges of the cheesecake.
Spread or pipe the whipped vanilla cream on top of the fully chilled cheesecake, creating soft swirls or rosettes.
Garnish the top with red velvet cake crumbs or drizzle with red glaze if using.
Slice with a sharp knife wiped clean between cuts and serve the cheesecake well chilled.