In the inner liner of your instant pot or pressure cooker, place 1.5 cups of water.
Place a steamer rack on top of it and place the pan with the pumpkin mixture on the rack.
Cover the pan with a silicone lid or aluminum foil.
Cook for 20 minutes at high pressure, and allow it to release pressure naturally for 10 minutes. Release all remaining pressure.
Remove lid carefully, not allowing any of the water on the lid to fall back into the pudding.
Chill for 6-8 hours and serve with additional whipped cream. I use this little device for the easiest whipped cream ever.
Oven Directions
Mix the ingredients together as instructed in the Instant Pot directions and pour them into a 6 x 3 pan.
Place the pan into a 13x9 pan and fill that pan halfway up with water.
Place the pans into the oven and bake at 350F for 40 minutes.
This is an easy dump and go recipe. Just mix everything in a bowl, cook, chill and serve.
The hardest thing about this is to ensure that you have greased that pan extremely well. Do not use a springform or push pan because when I tried that, the pudding starts to leak badly and you'll lose a lot of it. Thoroughly grease a baking pan well, let it cool a bit, and then empty it out onto a plate.
Definitely cover this with a lid or aluminum foil as you do not want moisture/steam going into your dessert. When you remove the lid, be careful you don't dump that water back into the pudding.
You really need to chill this dessert for the recommended time for the best results, especially if you use Erythritol, which is less likely to produce that cooling effect (or you're less likely to notice it) in a chilled dessert.