Preheat your oven to 325°F and wrap the exterior of a 9-inch springform pan with heavy-duty foil.
Combine graham cracker crumbs, melted butter, and 2 tbsp sugar, then press into the base of the pan.
Bake the crust for 10 minutes and let cool slightly.
Beat cream cheese, 3/4 cup granulated sugar, and brown sugar until smooth.
Incorporate pumpkin puree, sour cream, vanilla, cinnamon, and nutmeg until fully combined.
Add eggs one at a time on low speed, mixing just until incorporated.
Fold in the cornstarch.
Pour filling over the crust and place the springform pan into a large roasting pan filled with an inch of hot water.
Bake for 70 minutes until the edges are set but the center has a slight wobble.
Turn off the oven and leave the cheesecake inside for one hour with the door cracked.
Cool completely at room temperature, then refrigerate for at least 6 hours before serving.