Penny's Rib Rub, to taste
3 racks baby back ribs
2 tablespoons butter
1 large onion, finely chopped
2 tablespoons brown sugar
2 tablespoons lemon juice
2 tablespoons Worcestershire sauce
2 tablespoons apple cider vinegar
1 teaspoon salt
1 teaspoon paprika
1 teaspoon dry mustard
1 teaspoon chili powder
½ teaspoon cayenne pepper
1½ cups ketchup
½ cup water
Coat both sides of the ribs generously with rub (see related recipe); wrap in foil and refrigerate overnight.
For the sauce: Sauté onion in butter until soft, add remaining ingredients and simmer about 30-45 minutes. Makes about 3 cups. Refrigerate until ready to use.
To cook: Heat oven to 250 degrees. Spray wire rack with nonstick spray.
Place rubbed ribs in a single layer on a wire rack in a roasting pan with ½ inch of water. Tightly cover pan with aluminum foil and cook 4 hours, adding more water if pan gets dry.
Carefully remove pan from oven, being careful not to spill hot pan juice. Turn oven to broil or heat grill to high.
Place ribs on platter curved-side up and brush with sauce (you will not use all the sauce, save it for next time). Transfer ribs, right-side up, to a hot grill, or to a baking pan, and brush generously with sauce. Cook about 10 minutes, or until sauce starts to bubble and caramelize. Remove and serve.
Cook's note: Donna usually doubles/triples this recipe, as it keeps well in the refrigerator. But even when she triples the recipe, Donna never adds more than 1 teaspoon of cayenne; make sure to taste your sauce before deciding to add more.