Preheat the oven to 325 degrees F. Add a large roasting pan with several inches of water onto the lowest rack of the oven. Grease the bottom and sides of a 9-inch springform pan with shortening or butter. Set aside.
Start by making the crust. Add the graham crackers, sugar, and cinnamon to a food processor, and run at high speed until the graham crackers are fine crumbs.
Gradually pour in the melted butter while the food processor is running at low speed until well-mixed.
Pour the crumb mixture into the springform pan, and press them firmly into the base and slightly up the sides. Bake in the oven for 15 minutes.
While the crust is baking, make the cheesecake filling. In a large bowl, use an electric hand mixer and beat together the cream cheese, sugar, and flour until smooth.
Pour in the eggs and egg yolks, one at a time, and beat until they are just mixed. Add the vanilla extract in with the last egg, and set aside.
Now make the pumpkin layer. Whisk the pumpkin puree, brown sugar, pumpkin pie spice, and cinnamon in a medium bowl.
Pour about a third of the cheesecake filling into the pumpkin filling and whisk until just combined.
Pour the remaining cheesecake mixture into the springform pan, and smooth it out to the edges.
Pour the pumpkin mixture over the cheesecake layer, and spread evenly over the top.
Put the springform pan into the oven, on the rack just above the pan of water (not into the pan of water).
Bake for 1 hour and 10 minutes in the preheated oven. Turn off the oven, but keep the cheesecake in there for another hour. Do not open the oven door. You want to keep the heat trapped in there.
Take the cheesecake out of the oven and rest on a cooling rack for at least 30 minutes.
Cover the cheesecake with foil or plastic wrap, and put it in the refrigerator for 4 hours or until the cake is firm. Overnight is best.
When ready to serve, run a knife around the edge of the springform pan. Release the latch and remove the outer ring. Serve chilled with whipped cream.
Notes
Gingersnap cookies can be used in place of the graham crackers.
Store covered in refrigerator for up to 6 days. Or freeze for up to 3 months.