Place the ginger snaps into a food processor or gallon sized bag. Break up the cookies until they are finely broken up. Add in the melted butter and mix until well combined.

Press the wet crumbs firmly into the bottom and up 1 inch of the sides of a 7" springform pan. Put the pan in the freezer until ready to use.

In a large mixing bowl, blend the room temperature cream cheese and sugar until smooth. Add pumpkin, pumpkin pie spice, and vanilla and mix well. Add the room temperature eggs one at a time and mix on low speed just until blended. Do not overmix the batter.

transfer the batter into the springform pan on top of the crust.

Pour 1 cup of water into the pressure cooking pot and place the trivet in the bottom. Wrap a long 5-inch wide strip of foil around the outside of the pan to create a "sing" to lower and lift the cheesecake from the pressure cooker. Carefully center the springform pan on the foil strip and lower it into the pressure cooker. Be sure that the foil does not interfere with closing the lid.

Lock the lid in place. Select High Pressure and set the timer for 15 minutes. (25 minutes if you like a denser cheesecake.) When beep sounds, turn off pressure cooker and use a natural pressure release for 10 minutes and then do a quick pressure release to release any remaining pressure. When valve drops carefully remove lid.

Remove springform pan to a wire rack to cool. If there is a little water on top of the cheesecake, gently blot with a paper towel. When cheesecake is completely cooled, cover with plastic wrap and refrigerate for at least 4 hours or overnight.

When ready to serve, mix one cup whipping cream with 1 tablespoon of powdered sugar for a sweetened whipped cream. Spread the whipped cream over top, drizzle with caramel sauce and add a garnish of some crushed gingersnaps.