Preheat the oven to 350 degrees (F). Lightly spray a 9" springform pan with non-stick baking spray. Wrap the bottom and sides of the pan with heavy duty extra wide aluminum foil. I recommend doing several diligent layers here to ensure no water creeps through when you place the pan in the water bath. Set the pan aside.
In a large bowl, combine the graham cracker crumbs, sugar, salt, and melted butter. Mix well.
Press the crust into the prepared pan, pressing the crust down firmly and slightly up the sides. Bake in a preheated oven for 10 minutes. Place partially baked crust on a cooling rack and set aside while you prepare the filling. Reduce the oven to 325 degrees (F).
Make the filling:
In a very large bowl using a hand held mixer, beat the softened cream cheese and sour cream until completely smooth, scraping the bowl as needed.
Add in the eggs, egg yolks, pumpkin puree, sugars, and spices, and beat on low speed until just combined. Don’t over mix here or the batter will rise and fall in the oven! Add flour and vanilla and beat on low for another 30 seconds, or until flour has completely disappeared into the batter. Don't over mix!
Pour the filling into the crust, and spread evenly, smoothing the top. Place the springform pan into a large baking pan (with high sides) and fill the pan with 3 inches of hot water; this is your water bath.
Place the cheesecake in the oven and bake for 30 minutes, then reduce the temperature to 300 degrees and continue baking for another 55 minutes. Then turn the oven off and let the cheesecake sit, undisturbed, for 45 minutes, inside the oven with the door shut. The cheesecake should still be slightly wiggly.
Remove cheesecake from the oven, and run a knife very gently around the edge of the cake. Place the cheesecake on a cooling rack and cool completely, then loosely cover the pan with saran wrap and chill in the refrigerator for at least 6 hours.
Make the Whipped Cream:
In a large chilled bowl, using a handheld electric mixer, beat the heavy cream on medium-high speed, adding in the confectioners’ sugar a tablespoon at a time, until medium stiff peaks form. Add in the vanilla and beat for another minute or so. Swirl or dollops on top of cheesecake slices right before serving.