Chipotle-Citrus Ribs

Combine ¼ cup (packed; 50 g) light or dark brown sugar, 3 Tbsp. garlic powder, ¼ cup Diamond Crystal or 2 Tbsp. plus 2 tsp. Morton kosher salt, and 3 Tbsp. cumin in a medium bowl; season with freshly ground pepper. Pat 7–8 lb. St. Louis–style pork spareribs (about 3 racks) dry with paper towels and sprinkle brown sugar mixture all over (even edges), patting to adhere to meat as much as possible. Wrap each rack tightly in foil; crimp edges together to seal. Place on a rimmed baking sheet and chill at least 1 hour and up to 12 hours.

Place a rack in middle of oven and preheat to 300°. Bake ribs (directly from refrigerator, still wrapped in foil on baking sheet) until meat is very tender, 2½–3 hours. Unwrap and carefully pour off any accumulated liquid. Let cool.

Meanwhile, process 5–6 canned chipotles in adobo sauce, plus 2 Tbsp. adobo sauce, 1¼ cups orange marmalade (from a 13-oz. jar), 1 cup fresh orange juice, and remaining 2 tsp. cumin and 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt in a blender until smooth. Transfer to a small saucepan and cook over medium-high heat, whisking occasionally, until slightly thickened, 5–7 minutes. (It will continue to thicken as it cools and should reach the consistency of barbecue sauce.)

Prepare a grill for medium-high heat; oil grate with vegetable oil. Brush one side of ribs with sauce; place on grate, sauce side down. Brush other side with sauce. Grill, turning halfway through, until charred in spots, 7–9 minutes. Transfer to a cutting board.

Whisk ¼ cup fresh lime juice into remaining sauce. Cut between ribs to separate, then brush both sides with sauce. Arrange on a platter and scatter cilantro leaves with tender stems around. Serve with lime wedges for squeezing over.

Do Ahead: Ribs can be baked 1 day ahead. Rewrap once cool and chill.