Preheat oven to 325°F.
Mix graham cracker crumbs, sugar, and melted butter until combined.
Press crust mixture into the bottom of a 9-inch springform pan.
Bake crust for 10 minutes. Let cool.
In a large bowl, beat softened cream cheese and sugar until smooth.
Add pumpkin puree and mix until combined.
Beat in eggs one at a time, mixing after each addition.
Stir in vanilla, pumpkin pie spice, and heavy cream until smooth.
Pour filling over the cooled crust.
Wrap the bottom of the springform pan in foil and place it in a larger roasting pan.
Fill the roasting pan with hot water halfway up the sides of the springform pan.
Bake for 55-65 minutes, or until the edges are set and the center is slightly jiggly.
Turn off the oven and crack the door open to cool the cheesecake for 1 hour.
Refrigerate for at least 4 hours or overnight.
Serve with whipped cream and a sprinkle of cinnamon if desired.