Pre-heat the oven to 350 degrees. Take a 9 inch springform pan and grease the bottom of it liberally with butter or shortening. Either in a food processor or by hand in a ziplock bag with a rolling pin, crush the ginger snap cookies into a fine crumb.

Mix the ginger snap crumbs with the brown sugar, pumpkin pie spice, cinnamon, nutmeg and melted butter until it is like a uniform wet sand. Transfer the mixture to the prepared springform pan and press it very firmly into an even layer to form the crust. Bake the crust for 10 minutes to let it set. When it's done, take it out and set it aside. Reduce the oven heat to 325.

Meanwhile, prepare the luscious filling. In the bowl of a stand mixer fitted with the paddle attachment, beat together the cream cheeses, mascarpone cheese and pumpkin puree until they are thoroughly combined and fluffy. Add in the two sugars, pumpkin pie spice, cinnamon, nutmeg, salt and vanilla and let them get completely stirred in. The eggs and yolk get stirred in next, then finally the flour until it is a smooth batter.

Liberally grease the sides of the springform pan now with more butter so that the cheesecake doesn't stick to the sides. Transfer the batter into the prepared pan and put the pan on a sheet tray with a big lip. Put the tray in the oven, then carefully pour water into the tray around the sprinform pan. This keeps the top of the cheesecake from cracking. Let the cheesecake bake for about an hour and fifteen minutes, until cooked through and set.

When it's done, take it out and let the cake cool for about 10 minutes before releasing it from the springform pan. Let it cool for another 5-10 minutes before covering it and putting it in the refrigerator. Let the cheesecake chill for at least 3-4 hours before serving.

When you are ready to serve, cut the cheesecake into the desired sized pieces and drizzle each piece with prepared salted caramel sauce. Enjoy this decadent alternative to pumpkin pie!