Combine all dry rub ingredients in a small bowl.
Take a sharp knife and peel off the thin membrane on the backs of the ribs. (This step isn't completely necessary, but allows the rub to penetrate better.)
Rub dry rub into both sides of ribs. Wrap ribs in aluminum foil and place on a rimmed baking sheet lined with foil.
Bake in a 300 degree oven for 3 hours.
At least 30 minutes before the ribs are done, start making the glaze.In a medium saucepan, heat oil. Add onion and cook for about 4 minutes.
Add garlic and cook 1 minute.
Add remaining ingredients and simmer for 20 minutes, stirring frequently. You want the glaze to be thick enough to put a nice coating on the ribs. Simmer longer if necessary.
Remove ribs from oven and carefully unwrap them. Preheat broiler.
Baste the ribs with a thick coating of glaze . Broil for a few minutes, baste again and broil a few more minutes.
Serve with extra glaze.