4 ounces gingersnaps (about 18)
4 tbsp (1/2 stick) unsalted butter, melted
Nonstick cooking spray for the sides of the pan
4 8 ounce bars cream cheese, room temperature
1/ 1/2 cups packed light brown sugar
4 large eggs at room temperature
1/4 cup all purpose flour, spooned and leveled
1 tsp ground allspice
1 tsp ground ginger
1 tsp ground cinnamon, plus a little more for dusting
1/2 tsp kosher salt
1 15 ounce can pure pumpkin puree
3/4 cup heavy cream
1/4 cup sour cream
1 tbsp confectioners' sugar
Heat oven to 325º. In a food processor, pulse the gingersnaps until fine crumbs (about one cup). Add the butter and pulse to combine. Press the mixture into the bottom of a 9 inch springform pan (preferably nonstick), using straight-sided dry measuring cup to help. Spray the sides of the pan lightly with the cooking spray. Place the pan on a rimmed baking sheet.
Using an electric mixer, beat the cream cheese and brown sugar on medium until smooth, 1 to 2 minutes. Beat in the eggs, one a time. Add the flour, allspice, ginger, cinnamon and salt and beat to combine. Add the pumpkin and beat to combine. Pour the mixture into the prepared pan and bake until set but still slightly wobbly in the center (1 1/4 to 1 3/4 hours). Tent loosely with foil if the top becomes too dark.
Let cool completely in the pan, then refrigerate until firm, at least two hours. Run a knife around the edge of the cheesecake to loosen and then unmold.
Just before serving, using an electric mixer, beat the cream, sour cream and confectioners' sugar until soft peaks form. Dollop on the cheesecake and dust with cinnamon.