Combine all ingredients (except spaghetti sauce) until well mixed. Mixing together with your hands works great.Form into balls using hands or small ice cream scoop. You want them to be slightly smaller than a golf ball.
Spray bottom of Instant Pot with cooking spray and add spaghetti sauce. Place meatballs over the sauce, layering them if necessary. It's OK if they touch, just don't squish them too much.
Place lid on Instant Pot and switch valve to "sealing". Press "Manual" and set to high pressure for 7 minutes.
After you hear the timer go off, allow to slow release for another 5 minutes and then do the quick release (you do this by carefully switching the tab to "venting"). Remove lid from Instant Pot, stir, and serve over cooked pasta noodles.
Instant Pot Note: We use a 6-quart Instant Pot brand pressure cooker that we bought in 2016. Different or newer versions may be more sensitive to the "BURN" notice. If you are concerned about the burn notice, please refer to the Instant Pot webpage about Overheat Protection, found HERE.