Barbecued Beef Short Ribs

1 C. sugar
2 Tbsp. salt
1/2 C. brown sugar
2 Tbsp. garlic powder
2 Tbsp. paprika
2 Tbsp. pepper
1/4 tsp. cayenne pepper
7 lb. beef short ribs, trimmed

sauce:
1 sm. onion, finely chopped
2 tsp. vegetable oil
1 C. ketchup
6oz. can tomato paste
1 1/2 C. water
2 Tbsp. brown sugar
pepper to taste

In a bowl, combine first 7 ingredients. Rub over ribs. Place ribs in large, resealable, plastic bags; seal and refrigerate overnight. Line two 15 X10 X 1in. baking pans with foil; grease the foil. Place ribs in pans and bake uncovered at 325 degrees for 2 hrs or until meat is tender.
In a large saucepan, saute onion in oil until tender. Stir in remaining ingredients and bring to a boil. Reduce heat, cover, and simmer for 1 hr. Remove ribs from oven and grill covered over medium heat for 20 min. turning and basting often with the sauce.