Barbecued Baby Back Ribs with Louisiana Sweet Barbecue Sauce

To brine the ribs: Dissolve salt and sugar in 4 qt. cold water in large stockpot or large plastic container. Submerge ribs in brine and refrigerate 1 hour until fully seasoned. Remove ribs from brine and thoroughly pat dry with paper towels.

While ribs are brining: Cover two 3" wood chunks with water in medium bowl. Soak wood chunks for 1 hour, then drain and set aside. Combine spice rub ingredients in small bowl. When ribs are out of brine and dried, rub each side of racks with 1 Tbsp. spice rub; refrigerate racks for 30 minutes.

To barbecue ribs: Open bottom vents on grill. Ignite about 41/2 qt. charcoal briquettes and burn until covered with thin coating of light gray ash, about 20 minutes. Empty coals onto one half of grill bottom, piling them 2 to 3 briquettes high; place soaked wood chunks on top of coals. Position cooking grate over coals, cover grill, open lid vents 2/3 of the way. Heat grate 5 minutes, then scrape clean with wire brush.

Arrange ribs on cool side of grill parallel-to fire; cover and position lid so vents are opposite wood chunks to draw smoke through grill (grill temperature should register 350°F on grill thermometer, but will soon start dropping). Cook for 2 hours, until grill temperature drops to about 250 ° F, flipping rib racks, switching their position so rack that was nearest the fire is on the outside, and turning racks 180° every 30 minutes; add 10 fresh briquettes to pile of coals. Continue to cook (grill temperature should register 275°F to 300°F on grill thermometer), flipping, switching and rotating ribs every 30 minutes, until meat easily pulls away from bone, 1 1/2-2 hours longer. Transfer ribs to cutting board, then cut between bones to separate ribs. Serve.

For Louisiana sweet barbecue sauce: Heat butter in medium saucepan. Add onions and garlic; saute until onions soften, 3 to 4 minutes. Stir in next 6 ingredients; cook over medium heat to blend flavors, about 5 minutes. Meanwhile, dissolve brown sugar in the vinegar. Add vinegar/sugar mixture, molasses, sherry and tomato sauce; bring to simmer. Simmer uncovered until sauce thickens slightly, about 15 minutes. Serve.