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. Alternatively, you can use a 7-inch pan lined with parchment paper on the bottom and along the sides.
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.
Pour into pan on top of the graham cracker crust.
Run a fork back and forth through the cheesecake several times to remove air bubbles.
Mix all ingredients in the Chocolate Pecan layer, and pour over the top of the cheesecake.
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 Instant Pot.
Close the lid of the Instant Pot and turn to sealing 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.
Makes 6-8 servings.