How to Make It
Set a rack over a baking sheet and line the rack with 2 layers of paper towels. Spread the pumpkin puree over the paper towels and let drain for 2 hours, until the puree is fairly dry.
Preheat the oven to 500°. Butter the bottom and side of a 9-inch springform pan. In a food processor, pulse the graham crackers until finely ground. Add the pecans and brown sugar and pulse until finely ground. Add the melted butter and pulse just until incorporated. Press the crumbs onto the bottom of the prepared pan. Bake the crust for about 8 minutes, just until it is fragrant and lightly browned. Let the crust cool completely.
In the bowl of a standing electric mixer fitted with the paddle, beat the cream cheese until it is very smooth. In a small bowl, whisk the sugar with the salt, cinnamon, nutmeg, cloves and allspice. With the machine on, add the spiced sugar to the cream cheese and beat until creamy, scraping the bottom and side of the bowl. Carefully add the drained pumpkin puree and beat until smooth. Add the eggs one at a time, beating well and scraping down the bowl between each addition. Beat in the heavy cream, lemon juice and vanilla until the cheesecake mixture is smooth.
Pour the cheesecake mixture over the cooled crust and bake for 12 minutes. Lower the oven temperature to 225° and bake the cheesecake for about 3 hours, until an instant-read thermometer inserted in the center registers 150°; the center will be very jiggly but not liquidy. Let the cheesecake cool on a rack, then cover with plastic wrap and refrigerate overnight.
Run a hot knife around the cheesecake and loosen the springform ring. Carefully remove the ring and transfer the cake to a plate. Using a warm knife, cut the cake into wedges and serve with the Pecan Praline Topping and whipped cream.