Preheat oven to 300°F to 325°F
Remove membrane from the back of the ribs
Pat ribs dry
Season both sides with salt, pepper, and dry rub
Place ribs on a large sheet of heavy-duty foil
Wrap tightly in foil, sealing the edges well
Place wrapped ribs on a baking sheet
Bake for 2 to 2.5 hours for baby back ribs
Bake for 2.5 to 3 hours for spare ribs
Open foil carefully and check tenderness
Brush with barbecue sauce if desired
Uncover and bake 10 to 15 minutes more to caramelize sauce
Rest ribs for 5 to 10 minutes before serving