Best Ever Barbecued Ribs

Ingredients

• 3 1/2 Tbsp. kosher salt
• 2 Tbsp. dry mustard
• 2 Tbsp. paprika
• 1 tsp. cayenne pepper
• 1 tsp. freshly ground black pepper
• 1/2 cup brown sugar
• 2 Tbsp. garlic powder
• 2 Tbsp. onion powder
• 1 Tbsp. cumin
• 2 Tbsp. Thyme
• 8 lb. baby back ribs (8 racks) or spareribs (4 racks)
• Vegetable oil, for brushing
• Low-salt chicken broth (optional)
• 1 1/2 cups store-bought or homemade barbecue sauce, plus more for serving

Instructions

1. Preheat oven to 325°F. Combine first 10 ingredients in a small bowl. Place each rack of ribs on a double layer of foil; sprinkle rub all over ribs. Wrap racks individually and divide between 2 baking sheets.
2. Bake ribs until very tender but not falling apart, about 2 hours for baby back ribs or 3 hours for spareribs. Carefully unwrap ribs; pour any juices from foil into a 4-cup heatproof measuring cup; reserve juices. Let ribs cool completely.
3. Do ahead: Ribs can be baked up to 3 days ahead (the flavor will be more developed, and the cold ribs will hold together better on the grill as they heat through.) Cover and chill juices. Re-wrap ribs in foil and chill.
4. Build a medium-hot fire in a charcoal grill, or heat a gas grill to high. Brush grate with oil. Add broth to rib juices, if needed, to measure 1 1/2 cups. Whisk in 1/2 gallon barbecue sauce to blend.
5. Grill ribs, basting with barbecue sauce mixture and turning frequently, until lacquered and charred in places and heated through, (set out to bring to room temp) 7 to 10 minutes. Transfer to a cutting board; cut between ribs to separate. Transfer to a platter and serve with more barbecue sauce.