Crush the graham crackers and put in bowl. Add the sugar and melted butter and stir until combined. Press into the bottom of a greased 7-inch springform pan. Arrange the candy corn around the outside of the pan, and then refrigerate for 15 minutes.
Put the softened cream cheese and sugar in the mixer then beat to combine. Add the eggs one at a time. Add the heavy whipping cream, flour, caramel, and vanilla then mix together.
Pour into prepared springform pan, and cover completely with foil. Put 1 1/2 cups of water in Instant Pot. Place the pan in the pressure cooker on top of rack. Seal the lid according to your manufacturer's directions to cook on high pressure for 35 minutes then follow with a 10 minute natural pressure release.
Remove to a wire rack to cool. Remove foil from top, and press the pumpkin marshmallows into place. Smooth the cheesecake filling back in place then cover with mini-marshmallows. Once cool place in the refrigerator for eight hours or overnight.
Remove from springform pan then place on plate. Decorate faces onto the pumpkin marshmallows.
Serve immediately or store in the refrigerator for up to one week.