Remove the membrane from the back of the ribs and cut them into sections if necessary to fit in the Instant Pot.

In a small bowl, mix together the brown sugar, paprika, garlic powder, onion powder, salt, black pepper, and cayenne pepper. Rub this mixture all over the ribs.

Add water to the Instant Pot and place a trivet inside. Arrange the ribs on the trivet, standing them up if necessary. Close the lid and set the valve to sealing.

Cook on high pressure for 30 minutes. Once done, allow for a natural release for 10 minutes, then quick release any remaining pressure.

Remove the ribs and brush them with barbecue sauce. Optionally, place them under a broiler for 5 minutes to caramelize the sauce.

Slice the ribs between the bones and serve with additional barbecue sauce on the side.