Preheat oven to 350 degrees F (175 degrees C). Cut spareribs into serving size portions, wrap in double thickness of foil, and bake for 1 1/2 hours. Unwrap, and drain drippings. (I usually freeze the drippings to use later in soups.) Place ribs in a large roasting pan.
In a bowl, mix together brown sugar, ketchup, soy sauce, Worcestershire sauce, rum, chile sauce, garlic, mustard, and pepper. Coat ribs with sauce and marinate at room temperature for 1 hour, or refrigerate overnight.
Preheat grill for medium heat. Position grate four inches above heat source.
Brush grill grate with oil. Place ribs on grill, and cook for 30 minutes, basting with marinade.
