For the cheesecake crust:

1. In a large bowl, stir together Graham cracker crumbs and melted butter until well mixed. If you are using whole crackers, add the crackers into a food processor and process until fine crumbs form.
2. Press crumb mixture firmly into a parchment-lined 8-inch springform pan and freeze for at least 15 minutes, allowing the crust to set before filling.

For the cheesecake filling:

1. In a large mixing bowl, add heavy cream and whip with a hand mixer or by hand until stiff peaks form, about 3-4 minutes. Set aside. In a medium mixing bowl, mix cream cheese (at room temperature), pumpkin puree, sugar, vanilla extract, pumpkin pie spice and salt using the hand mixer until smooth, about 2 minutes. Set aside.
2. Optionally, dissolve 1 pack (15 ml) gelatin powder in 1/4 cup water in a bowl according to package instructions. Pour gelatin over water and let it stand for 1 minute. Microwave on high for 15 seconds (or warm up the jar in a hot water bath) for 1 minute and stir well until gelatin is completely dissolved.
3. Add the dissolved gelatin and whipped cream to the pumpkin cheese mixture and stir until well combined.
4. Pour the filling into the cooled crust and smooth out the surface with a small icing spatula. Cover the cheesecake in the springform pan with aluminum foil and refrigerate for at least 4 hours or overnight to set completely.
5. Once completely set, run a knife along the wall of the springform pan to separate the cheesecake. Slice and serve with whipped cream if desired.