Grease the bottom and sides of the springform pan generously with butter. Wrap the bottom of the pan with aluminum foil to prevent leaking. To the inner pot, add 1 ½ cups of water.
In a small bowl mix the crushed oreo, 2 tablespoons of white sugar, and melted butter to make the oreo crust. Line the bottom of the greased cheesecake pan with the cookie crumble. Press down with your fingers so that it is packed firm. You can also press some of the crust up the sides of the pan. Put the pan in the freezer to harden the crust while you prepare the filling.
Use an electric hand mixer or stand mixer to beat the sugar and softened cream cheese on medium speed until smooth, about 60-90 seconds.
Add the peppermint extract, melted white chocolate chips and creme de menthe. Beat on medium speed until smooth, about 60 seconds. Taste, and add 1 to 2 more tablespoons of creme de menthe if desired. (see notes if not using the creme de menthe liqueur)
Add the eggs and beat on low until they are just incorporated, about 20 seconds. Be careful not to overmix or mix on a higher speed, as this could put too much air into the cake.
Pour the filling into the pan. Tap lightly on the counter to remove air bubbles. Cover tightly with aluminum foil. Put the pan on the silicone sling and place into the inner pot.
Close and seal the lid. Set to pressure cook on high for 35 minutes. Allow a full natural release (about 20 minutes) when done.
Open the lid and remove the foil from the top of the cheesecake, being careful not to let any water on the foil fall onto the cheesecake. If there is water on the cheesecake, gently blot with a paper towel. Put the lid back on the Instant Pot but keep it slightly cracked. Let the cheesecake come to room temperature in the Instant Pot for about 1 hour.
Lift the sling out of the pot and transfer the cheesecake to the counter. Unlock the pan and slowly remove the side. Cover with plastic wrap. Allow to chill in the fridge for at least 4 hours (preferably overnight) before adding your toppings and serving.