Preheat oven to 350 °F (175 °C).
Combine gingersnap crumbs, sugar, and melted butter in a bowl until evenly moistened.
Press the crust mixture firmly into the bottom and slightly up the sides of a 9-inch springform pan.
Bake the crust for 8 to 10 minutes, then allow it to cool while preparing the filling.
In a large bowl, beat the softened cream cheese and sugar until smooth and creamy.
Add pumpkin puree and mix until fully combined.
Beat in eggs one at a time, then add the vanilla extract and spices, mixing well after each addition.
Fold in sour cream if using for extra creaminess.
Pour the filling over the cooled crust in the pan.
Bake for 50 to 60 minutes, until the center is just set and still slightly jiggly.
Turn off the oven, crack the door, and let the cheesecake cool inside for 1 hour to prevent cracking.
Refrigerate the cheesecake for at least 4 hours or overnight before serving.
Run a knife around the pan edge and release the springform before slicing and serving.