Preheat oven to 350° F if not still preheated.
In the bowl of a stand mixer, mix the cream cheese, sugar and cornstarch together with a paddle attachment for two minutes on medium speed until everything is smooth and there are no lumps. (You can alternatively use a hand mixer). Scrape down the sides and bottom of the bowl to ensure everything has been mixed well.
32 oz (907 g) cream cheese, softened at room temperature, ¾ cup (150 g) granulated white sugar, 2 tablespoon (16 g) corn starch
Add in the vanilla bean paste, sour cream and melted and cooled white chocolate and mix for 1 minute on medium speed. Scrape sides and bottom of bowl again.
8 oz (226 g) white chocolate, melted and slightly cooled, ⅓ cup (82 g) sour cream, at room temperature, 1 tablespoon vanilla bean paste or extract
At this point, stop and put a pot of water on the stove to start boiling. You will want enough water to go about 1 ½ inches up the sides of the springform pan.
Next add in the eggs and egg yolks one at a time to the cheesecake batter. Mix on low speed, ensuring that each is fully mixed in before adding the next. As soon as the last one is fully mixed in, turn off the mixer. Do not over mix the batter.
3 eggs, at room temperature, 3 egg yolks, at room temperature
Pour the batter into the prepared pan with the crust.
Place the cheesecake in a large roasting pan in the oven. Slowly pour the boiling water into the pan around the cheesecake being careful not to splash the cheesecake.
Bake at 350° F for 1 hour. When 1 hour is up, turn off the oven and crack the oven door open using a wooden utensil. Let the cheesecake stay in the oven for 1 more hour. The cheesecake will continue to bake as it is cooling.
Once the 2 hours are up, remove from the oven and go around the edges of the pan with a butter knife to loosen the crust from the sides of the pan. Let the cheesecake cool completely on the counter, and then refrigerate until completely cold, 8 hours or overnight.