Pre-heat oven to 350 degrees F.
In a medium sized bowl, combine crushed gingersnaps, pecans, sugar and butter.
Press the mixture evenly onto the bottom of the prepared springform pan.
Bake 8-10 minutes or until set. Let cool.
In a small bowl, combine sugar, salt and spices.
In the bowl of an electric mixer on low speed, beat the cream cheese until smooth (about 2 minutes) Gradually add the sugar mixture and beat until creamy and smooth (1 to 2 minutes). Add eggs, one at a time, beating well after each addition, scraping down sides of the bowl each time.
Mix in the vanilla extract and pumpkin puree.
Pour the filling over the crust and place springform pan inside of a larger roasting pan. Fill roasting pan with boiling water 1/2 way up the sides of the springform pan.
Bake the cheesecake for 30 minutes, then reduce the oven temperature to 325 degrees F. and continue to bake the cheesecake another 10-20 minutes, or until the edges of the cheesecake are puffed, but the center is still a little wet and jiggles when you gently shake the pan. Total baking time 40-60 minutes.
After removing the cheesecake from springform pan, gently press sugared pecans around edge of crust if desired.