Combine graham cracker crumbs with sugar and melted butter and pat down on the bottom of a 7-inch springform pan sprayed with non-stick cooking spray.
Cream together the cream cheese and sugar until smooth and then mix in the eggs one at a time. Mix in the vanilla extract and sour cream until smooth.
Mix in the peanut butter.
Pour half of the batter into springform pan on top of the graham cracker crust.
Add Reese's peanut butter cups.
Pour the remaining batter on top of the peanut butter cups.
Cover with foil.
Pour two cups of water into the inner pot of the Instant Pot.
Make a sling out of aluminum foil to lower the pan into the pressure cooker.
Close the lid of the Instant Pot and turn to seal position.
Set for a manual high-pressure time of 35 minutes. When the time has finished, allow for a natural release for 12 minutes before letting out the rest of the steam.
Cool on the counter for an hour and then put in the refrigerator and cool for an additional 4 hours.