Created by JostLori on November 25, 2013
Step 1: Preheat oven to 350 degrees. Butter a 9-by-13-inch baking dish; set aside.
Step 2: In a large bowl, combine melted butter, graham cracker crumbs, and sugar; stir until well combined. Press graham cracker mixture into bottom of prepared baking dish in an even layer; set aside.
Step 3: In the bowl of an electric mixer fitted with the whisk attachment, whisk together cream cheese, eggs, and sugar until fluffy.
Step 4: Spread cheesecake mixture over crust in baking dish. Transfer to oven and bake for 20 minutes. Remove from oven and let cool.
Step 5: Place 1/4 cup water in a small bowl, then sprinkle gelatin over the top and let it soften.
Step 6: In a large heatproof bowl, mix together pumpkin, egg yolks, 1/2 cup sugar, milk, salt, and cinnamon. Set the bowl over (but not touching) simmering water; whisk pumpkin mixture until thickened, 8 to 10 minutes.
Step 7: Remove bowl from heat and whisk in gelatin mixture. Let cool to room temperature.
Step 8: Once the pumpkin mixture is cooled, in the clean bowl of an electric mixer fitted with the whisk attachment, beat egg whites until soft peaks form. Add remaining 1/4 cup sugar and continue whisking until medium peaks form.
Step 9: Fold the egg whites into cooled pumpkin mixture. Spread pumpkin mixture over cheesecake; Cover and transfer to refrigerator until set, at least 8 hours and up to overnight.
Step 10: In the bowl of an electric mixer fitted with the whisk attachment, whisk together the heavy cream, sugar, and vanilla until soft peaks form. Spread over cake or serve cheesecake with a dollop on the side.