Rub each rack of ribs all over with two tablespoons of the Garlicky Barbecue Marinade and refrigerate overnight.
Bring the ribs to room temperature and sprinkle each rack with one tablespoon of the Seven-Spice Dry Rub.
Light a charcoal fire in a covered grill and set it up for indirect grilling: when the temperature reaches 225°F, carefully push the hot coals to one side and place a drip pan filled with one cup of water on the opposite side. Alternatively, bring a smoker to 225°F.
Put the ribs on the grill over the drip pan, overlapping them slightly, and cover the grill; you’ll need to cook the ribs for about four hours total, or until the meat pulls away from the bones and is very tender. Maintain the temperature at 225°F by replenishing the charcoal with a fresh batch of burning coals every hour. Every hour, drain 1/2 cup of the wood chips and scatter them over the hot coals. Add water to the drip pan when half of it is evaporated. After 1 1/2 hours, spray the baby back ribs with the Cider Mop Spray and rotate them on the grill; repeat spraying every 45 minutes.
Remove the drip pan and spread the coals in an even layer. Replenish with fresh coals to make a medium-hot fire. Brush the ribs with the diluted Sweet and Sticky Barbecue Sauce and cook for 30 minutes, turning often. Repeat brushing 4-5 times to build a sticky glaze. Transfer the ribs to a carving board and let rest for 10 minutes. Cut between each rib and serve.
Tip: The glazed ribs can be refrigerated overnight if you want to make this dish more than a day ahead. Serve cold or reheat in a 325°F oven.