Line springform pan with parchment paper, no need to grease the paper. Set aside. Create a tin foil sling to lower pan into the Instantpot and remove when done cooking. Set aside.
In a small bowl place the 1/4 cup melted butter and pinch of salt. Stir in graham crumbs. Press mixture into springform pan using back of spoon or a glass. Freeze for approximately 20 minutes while you prepare batter.
In a small bowl, stir together cornstarch, salt and white sugar.
Using a hand mixer (stand mixers incorporate too much air into the batter), beat cream cheese till it begins to smooth out. Mix in sugar mixture above. Add small amounts and incorporate as you go so you don't end up with sugar and cornstarch everywhere! Do not overmix.
Add sour cream and vanilla. Again do not overmix or you will end up with a really puffy cheesecake. Blend in eggs.
Pour into prepared pan and tap the pan on counter several times to remove any air bubbles. Remaining bubbles can be removed by popping with a fork or toothpick.
Pour 1 cup water into bottom of Instantpot. Add steamer rack in the bottom and place cheesecake on the rack using the foil sling you made above. Put on lid and lock in place. Set Instantpot to High Pressure for 26 minutes. Once cooking time is complete, let pressure release naturally for about 7 minutes before removing cheesecake from Instantpot.
Cool for 10 minutes and run a small knife around inside or parchment paper. Remove springform and cool on wire rack. Store in fridge, removing parchment paper before cutting.