GINGERSNAP CRUST

1. Preheat oven to 350 degrees.  Butter the bottom of a 9-inch springform pan and line it with parchment or wax paper.  Set aside.
2. In a medium bowl, mix together the crushed gingersnaps, sugar, butter, and salt.  Press the mixture into the bottom and 1/2-inch up the sides of the pan.  Bake for 9 to 10 minutes until the crust feels firm.  Remove from oven set aside to slightly cool while you make the batter.
3. Reduce oven temperature to 325 degrees.

CREAM CHEESE BATTER

1. Add the cream cheese to the bowl of a stand mixer fitted with the paddle attachment.  Beat on medium-high speed until the cream cheese if silky smooth and free of any lumps.  Add the granulated sugar and beat on medium speed for 2-3 minutes until the mixture is smooth and no longer grainy.  Add the sour cream, flour, and vanilla and beat until smooth.  Add the eggs, one at a time, beating after each addition until well combined.  

PUMPKIN SPICE BATTER

1. Add 2 cups of the cream cheese batter to a medium bowl.  Add the pumpkin puree, and pumpkin pie spice and mix by hand with a spoon until well combined.
2. Layer batters in pan: Pour 2 cups of the remaining cream cheese batter over the crust, smoothing it out with an offset spatula.  Pour 1 cup of the pumpkin spice batter into the center of the cream cheese batter.  Using a large spoon, randomly drop spoonfuls of both of the remaining batters over the surface.  Using a knife, swirl the batters together.  To get a full marbled effect, make sure you insert the knife almost to the bottom crust before swirling. 
3. Wrap the bottom and sides of the pan with a large sheet of foil, shiny side out.  Place the pan in a large roasting pan or a 1/2 sheetcake pan (that’s what I use).  Fill the pan with enough boiling water to come 1-inch up the sides of the springform pan.
4. Bake the cheesecake on the center oven rack until the center is set, but still slightly jiggly, about 1 hour and 45 minutes.
5. Carefully remove the springform pan from the water bath and let it cool completely on a wire rack.  Remove the foil and refrigerate overnight until chilled and firm.
6. Slice and serve with a dollop of whipped cream and garnish with pumpkin pie spice, if desired.