Grease the sides and bottoms of a 6-inch push pan and line the pan with a parchment round. Alternatively, you can also line the sides of the pan with parchment paper.
In a food processor, combine graham cracker crumbs, sugar and melted butter and pulse to mix ingredients. Then, press crust out on the bottom of the pan and ½ way up the sides. You can use the bottom of a glass to press down the crust.
Place pan in the freezer while making the filling. Freezing will help hold the crust together.
Mix the cream cheese and granulated sugar until nice and smooth, and then add in one egg at a time while mixing in between adding the eggs.
Add in the flour, cocoa powder, sour cream and vanilla and mix to incorporate.
Stir in chocolate chips.
Pour the filling into the push pan and tap the pan several times on the counter to remove air bubbles. You can also run a fork or knife through the cheesecake filling to remove air bubbles.
Cover the cheesecake with aluminum foil and/or a paper towel to prevent condensation from accumulating on the top of the cheesecake.
Add 1 ½ cups of water to the inner pot of the Instant Pot.
Using a sling (you can buy a sling for the Instant Pot or make one out of foil), lower the pan into the inner pot.
Close lid and set for a manual high-pressure cooking time of 30 minutes. Allow for a natural pressure release when the cooking time has finished.
Remove the cheesecake from the Instant Pot. Take the foil off of the top and gently soak up any condensation that has formed on the top of the cheesecake with a paper towel or flour sack towel.
Let the cheesecake cool on a wire rack for at least an hour before refrigerating for 12 hours or overnight.
After 12 hours, remove the cheesecake from the refrigerator and set the pan on top of a large can. Push the sides of the cake pan down, slowly.
Remove the cheesecake from the pan bottom, and set on a cake plate or serving tray.