Add the cream cheese and sugar to the bowl of a stand mixer fitted with a paddle attachment. Beat together on high speed for 1-2 minutes, or until smooth and creamy and no lumps remain.
32 ounces cream cheese, 1 cup granulated sugar
Add the heavy cream, Biscoff butter, sour cream, and salt and beat together for 1 minute to fully incorporate. Add the eggs and beat together. Add the flour and mix to incorporate.
1¼ cups heavy cream, ½ cup Biscoff cookie butter, ⅓ cup sour cream, 1 teaspoon kosher salt, 4 large eggs, 2½ tablespoons all-purpose flour
Pour the cheesecake batter into the springform pan on top of the crust and smooth out.
Wrap the bottom and sides of the springform pan with foil to prevent water from seeping in.
Place the springform pan into a larger baking pan or broiler pan. Fill the larger pan with enough hot water to come 1 inch up the sides of the springform pan. Place both pans into the oven to bake for 90 minutes. To prevent the cheesecake from browning excessively, you may want to tent a piece of foil over the surface of the cheesecake after 45 minutes of baking, ensuring that the foil does not touch the cheesecake surface.
Once baked, turn the heat off and leave the cheesecake in the oven to set for 1 hour with the door closed.
Once set, remove from the oven, unwrap the foil and place the springform pan onto a cooling rack to cool completely.