In a bowl, make a dry rub by combining the sugar, Essence, salt, cumin, paprika, black pepper, and cayenne, and mixing well. Rub the ribs evenly on both sides and wrap in plastic wrap. Place on a baking sheet and refrigerate at least 6 hours or overnight.
Soak wood chips of choice in a bucket of water for 2 to 3 hours, then drain. Prepare a smoker according to the manufacturer's instructions. Remove the ribs and unwrap. Place on the grill of the smoker and cook for 1 1/2 hours, replenishing the coals as needed during the cooking time.
Remove the ribs from the grill and remove the smoker pan or box. Return the ribs to the grill and baste with the Barbecue Sauce. Cook, turning and basting once, until cooked through, 10 to 15 minutes. Remove from the grill and serve with additional sauce on the side.
Yield: 4 servings