Line the bottom of a 7-inch springform pan with parchment paper.
Make the Crust
Combine the crushed graham crackers and butter in a small bowl. Stir with a fork until well combined, then press the mixture firmly into the bottom of the springform pan to form a crust.Place the pan in the fridge while you prepare the filling.
Make the Cheesecake Filling
Using a hand mixer or stand mixer fitted with a paddle attachment, blend the cream cheese on high speed until smooth. Add powdered sugar, eggs, vanilla, and pumpkin puree, and blend on high speed until well incorporated.
Remove springform pan from the fridge. Pour the filling over the chilled crust and cover the pan with aluminum foil.
Prepare your Instant Pot. Add one cup of water to the inner pot. Set a trivet in the water and place your covered springform pan on top of the trivet.
Place the lid on your Instant Pot, lock it, and set the pressure valve to "Sealing". Manually set the IP to cook on high pressure for 35 minutes. It will take about 5 minutes to come to pressure.
When the cook time ends, allow the pressure to release naturally. This will take about 20 minutes.
Leave the pumpkin cheesecake in the pan and transfer it to the freezer for 2 hours, or the fridge for 4-6 hours, to allow to set completely.
Just before serving, remove the springform pan and cut the cheesecake into 8 slices.
Notes
For the creamiest cheesecake, use full fat cream cheese.
Chill the cheesecake until just before serving. To create clean slices, use a sharp knife, and cut the dessert while it is still cold. Use paper toweling to wipe off the blade of the knife between each cut.
StoringKeep any leftovers in the refrigerator, and use within 4 days. For longer storage, the cheesecake will keep for up to 3 months in a freezer. To prevent it from freezer burn, wrap the cake well with a layer of plastic wrap, and cover that with a layer of heavy duty aluminum foil.