Pork Spareribs With Jammy BBQ Sauce

Mix 3 Tbsp. Diamond Crystal or 1 Tbsp. plus 2¼ tsp. Morton kosher salt, 3 Tbsp. light or dark brown sugar, 2 Tbsp. smoked paprika, 2 Tbsp. garlic powder, 1 Tbsp. onion powder, and 1 Tbsp. mild curry powder in a small bowl to combine. Pat 2 racks St. Louis–style pork spareribs (3½–4 lb. total) dry with paper towels; remove silverskin from bones (lift and loosen with a knife and it should pull away in a single sheet; removing allows spices to penetrate the meat better and avoids a tough texture) and discard. Season all over with rub, concentrating most of it on meat side and patting to adhere. Wrap each rack in a double layer of foil, crimping edges together to seal. Place each on a rimmed baking sheet. Chill at least 1 hour and up to 1 day.

Place racks in upper and lower thirds of oven; preheat to 300°. Bake foil-wrapped ribs until meat is fork-tender at the thickest part but not falling off the bones (poke meat through foil with a fork to check; aim for a spot between the bones), 2–2½ hours. Let cool slightly, then unwrap if finishing immediately. Do ahead: Ribs can be baked 1 day ahead. Let cool completely, then chill.

Cook ¾ cup strawberry jam or preserves or other seedless jam, ⅓ cup double-concentrated tomato paste, 2 Tbsp. hot sauce, 2 Tbsp. Worcestershire sauce, 1 Tbsp. apple cider vinegar, 1 Tbsp. yellow mustard, 1 tsp. mild curry powder, and ¼ cup water in a small saucepan, whisking often, until thickened slightly, about 5 minutes. Season glaze with kosher salt.

Prepare a grill for medium heat; oil grate. Cut each rack in half (for ease of handling). Grill ribs, turning and basting with glaze several times as soon as meat begins to brown, until charred, thickly coated with glaze, and heated through, 8–10 minutes. (Or, place a rack in upper third of oven; heat broiler. Arrange ribs, meat side up, on a foil-lined baking sheet. Brush with a thin layer of glaze; broil until ribs are blistered and charred in spots, about 3 minutes. Repeat glazing process a few more times to build up a layer of glaze.) Transfer ribs to a cutting board and brush one more time with glaze. Cut between bones to form individual riblets.

Arrange ribs on a platter and serve with any leftover sauce alongside. Do ahead: Glaze can be made 1 day ahead. Let cool; cover and chill.