At least 1 hour before smoke-cooking, soak wood chunks (for smoker method) or wood chips (for grill method) in enough water to cover.
For the dry rub, in a small bowl combine granulated sugar, 4 teaspoons brown sugar, salt, onion, garlic, ground white pepper, ground black pepper, cumin, paprika and chili powder. Reserve 2 teaspoons of this mixture and place in a second small bowl. Sprinkle the remaining rub over both sides of the ribs; rub mixture into ribs. Stir 1 tablespoon brown sugar into the reserved rub mixture; set aside. Makes 4 servings.
Drain wood chunks. In a smoker arrange preheated coals, drained wood chunks and water pan according to manufacturer's directions. Pour water into pan. Place ribs on the grill rack over the water pan. Cover and smoke for 3 to 4 hours or until tender. The last 15 minutes of smoking, sprinkle the reserved brown sugar-rub mixture over the ribs. Brush with your favorite barbecue sauce the last 5 minutes of smoking.
Drain wood chips. In a grill with a cover arrange preheated coals around a drip pan. Test for medium heat above pan. Sprinkle drained chips over the coals. Place ribs on the grill rack directly over the drip pan. Cover; grill until tender (allow 1-1/4 to 1-3/4 hours for spareribs or 1-1/2 to 2 hours for loin back ribs). The last 15 minutes of grilling, sprinkle the reserved brown sugar-rub mixture over the ribs. Brush with your favorite barbecue sauce the last 5 minutes of grilling.