Grease a 7 inch springform pan evenly and generously with butter. Wrap the outside of the pan in foil. (proceed to step 3 if making crustless)
In a large bowl, mix the crushed graham crackers, white sugar, nutmeg, and cloves. Add the melted butter and mix well. Pour into springform pan and press down so the crumbs hold together. Place into the freezer while preparing the filling.
In a separate large bowl, beat brown sugar and cream cheese on high speed until smooth, about 3 minutes. Add the pumpkin puree, vanilla extract, pumpkin spice seasoning and salt. Beat on high until smooth, about 3 more minutes.
Add the eggs and mix on low until just incorporated, about 20 seconds, being careful not to overmix. Fold any remaining egg into the batter with a spatula.
Prepare the Instant Pot by filling it with 2 cups of water. Insert a silicone sling into the inner pot and put the springform pan on the sling. Pour the cheesecake filling into the pan. Cover tightly with foil, securing the sides.
Close and seal the Instant Pot lid. Set to pressure cook on high for 45 minutes.
When done, let complete a natural release for at least 30 minutes. Then quickly release remaining pressure. Remove the lid and wipe away condensation from the inside of the lid.
Carefully remove the foil covering the cheesecake. There may be a small amount of water on top of the cake. Blot this away with a paper towel. Keeping the cheesecake in the Instant Pot, place the lid back on and let sit for 1 hour.
Remove the lid from the Instant Pot. Transfer the sling and cheesecake pan to the counter carefully. Put the cheesecake in the fridge to cool overnight, or for at least 5 hours before removing from the pan.
Unlock the springform pan and slowly open it. If the sides of the cheesecake are stuck to the pan, slide a knife between the cake and the pan to loosen it. The cheesecake can be left on the pan's bottom to serve or transfered to a serving platter.
Top with whipped cream, caramel sauce, and pecans or walnuts to serve.