Grease a 6" or 7" springform pan* or a 1-1/2 quart casserole dish
that fits inside your Instant Pot
. Set aside.
Add all crust ingredients to a mixing bowl and mix until thoroughly combined.
Dump the mixture into your greased pan and press down to form a "packed" crust at the bottom. Don't worry about pressing it up the sides; you want it to form a nice, thick crust on the bottom.
Transfer the crust to the freezer for 15 minutes, while you prepare the pumpkin pie filling.
In a large mixing bowl or stand mixer fitted with the paddle attachment, mix together all filling ingredients except the water. The mixture should be completely smooth.
Pour the pumpkin pie filling into the frozen springform pan.
If using a casserole dish, cover with the glass lid. If not, place a piece of unbleached parchment over the springform pan and secure it with a piece of aluminum foil.
Add the 1 cup water to your Instant Pot.
Place the trivet inside the pot.
Place the covered pie on top of the trivet.
Secure the lid on the Instant Pot, making sure the steam release valve is sealed.
Press the "Manual" button, and adjust the time to 35 minutes.
When the Instant Pot beeps, press "Keep Warm/Cancel" Allow the Instant Pot to release pressure naturally for 15 minutes.
Then, release the remaining pressure and remove the lid from the Instant Pot.
Using oven mitts, carefully lift the trivet with the pumpkin pie out of the Instant Pot.
Allow the pie to cool to room temperature while covered.
Once cooled, remove the lid (or parchment + foil), taking care not to drip any condensation onto the pie.
Gently run a knife around the edges of the pan or dish. This will help loosen it until you're ready to remove it from the pan to serve.
Wipe off all condensation from the lid (or parchment + foil) and return it to the top of the pie.
Place the covered pie in the fridge to set for at least 4 hours, preferably overnight.
Serve chilled as-is or with homemade whipped cream (or coconut cream for dairy-free), orhomemade vanilla or cinnamon ice cream.