Special equipment: a 10-inch springform pan
Preheat the oven to 325 degrees F.
For the crust: In a large skillet over medium-high heat, cook the bacon until crispy, 1 to 2 minutes on each side. Remove to a paper towel-lined plate. Reserve 3 tablespoons of the rendered bacon fat. When the bacon is cool enough to handle, coarsely chop.
In a food processor, add the gingersnap cookies, cinnamon and bacon. Pulse until the cookies and bacon are both crumbs. In a large bowl, mix the crumb mixture, reserved bacon fat and butter until moist.
Evenly press the cookie mixture into the bottom and 2 inches up the sides of a 10-inch springform pan. Bake the crust for 8 minutes. Remove and let cool.
For the filling: In a stand mixer, beat the cream cheese and sugar until smooth. Beat in the flour, ginger and nutmeg. Beat in the eggs 1 at a time, scraping down the sides of the bowl as needed. Beat in the pumpkin, molasses and vanilla. Do not overmix. Pour the filling into the cooled crust.
Fill a roasting pan halfway with water and put on the lower rack of the oven; this should help prevent the top of the cheesecake from cracking. Put the springform pan on a rack above the water and bake the cheesecake for 1 hour 45 minutes. Remove the cheesecake and run a knife around the pan, separating the cake from the pan; this releases any tension when the cake cools. Return the cake to the oven, turn the oven off and slightly open the oven door. Let the cheesecake cool in the oven for another hour. Remove from the oven and let cool completely. Chill in the refrigerator for a minimum of 12 hours before serving.