Melt the butter in a pan over medium-low heat until it begins to brown. Add graham cracker crumbs and mix well.
Pour the graham cracker mixture into the springform pan and press gently with spoon.
Using an electric mixer mix the cream cheese on low until smooth. Add sugar and flour while continuing to mix.
Pour the heavy cream and Baileys, mix on medium speed for 1 min. Add the eggs, one at a time, and mix on low speed just until eggs are incorporated.
Pour the batter over the crust and gently tap the side of your springform pan to help any trapped air come to the surface. Cover with foil.
Add 1 cup of water to the instant pot and put a trivet on the bottom of the pot. Place springform onto trivet. Cover, set to sealing, and cook on high pressure (manual) for 35 minutes.
Allow for a natural release (about 15 minutes) then place cheesecake in the refrigerator to set.
While cheesecake is setting, prepare the ganache by heating the heavy cream just to a gentle simmer, either on the stove top or in the microwave (about 3 minutes on high power). Add chocolate and baileys, then whisk or blend (I like to use an immersion blender) until smooth. Allow to cool to room temperature.
Pour cooled ganache over cheesecake, then return to refrigerator to set. Garnish cheesecake with whipped cream and cocoa powder before serving, if desired.
Notes
Calories are automatically generated. For best results calculate based on your exact ingredients.