lightly grease a round baking pan or casserole dish, and pour peaches into pan
Use a knife to cut peaches in half, then stir in cinnamon
Pour cake mix over peaches, and lightly swirl with knife
Add slices of butter evenly over cake mix
Pour water into Instant Pot, and place trivet in pot
Place baking dish on top of trivet, and place a sheet of aluminum foil lightly over baking dish
Place lid on Instant Pot, turn vent to sealing position, and hit PRESSURE COOK for 25 minutes
Allow a 5 minute natural release, then do a quick release
When pin drops, remove lid and carefully lift handles of trivet (using oven mitts) to remove from pot, and remove foil.
Place peach cake in oven, and broil for about 5 minutes or until top is golden. Remove from oven, and allow to cool slightly before serving