For one full rack or three baby backs, make a rub of 1 cup light brown sugar and a quarter cup of paprika with a tablespoon each of cumin, granulated garlic, black pepper, and salt. Some people like cayenne; I’d advise against it. Cut ribs to fit roasting pan, pat dry, oil, and coat with rub. Place pan in middle oven with a quart container of water on the bottom. Set oven at 350 for first hour, then turn the ribs and reduce heat to 225. Turn in another hour, then cook until meat is tender, about 2 1/2 to 3 hours for full racks, half that for baby backs.
