In a big mixing bowl, add the room temperature cream cheese, sour cream, and the cooled melted white chocolate, and mix with an electric hand mixer until the cream cheese is creamy.
Add the sugar, egg yolk, and vanilla extract and mix until the mixture is creamy and smooth.
Lower the hand mixer speed to low, and add each egg at a time. This step stops the cheesecake batter from overbeating. Add the heavy cream, and kosher salt, and mix until just combined.
Pour the cheesecake batter over the crust, filling each mold until it’s almost full, and release air bubbles by tapping the pan onto a flat surface.
Bake the cheesecakes in a preheated 140c (280f) oven for about 15 minutes or until the edges of the cheesecakes are set, but the middle is a bit jiggly. Keep the oven door closed for 5 minutes.
Open the oven door halfway, and let the cheesecake cool to room temperature for 1-2 hours.
After the cheesecake is cooled, wrap the cheesecake with a plastic wrap tightly, and place the cheesecake in the fridge to cool completely for at least 5 hours.