Pat the ribs dry and season them all over with the salt and pepper. Heat the oil in a large heavy skillet on medium-high. Add the ribs and sear them until deeply browned all over, 3 to 4 minutes per side (cook in batches or use two skillets if necessary). Transfer the ribs to a 4-quart slow cooker.
Add the water to the skillet, scraping the pan bottom. Remove the pan from the heat and stir in the barbecue sauce, molasses, paprika, coriander, and thyme. Pour the sauce over the ribs and turn them until they’re coated evenly. Cover and cook on low for 4 hours or high for 2½ hours. The ribs should be very tender.
When the ribs are tender, heat the broiler. Line a baking sheet with foil and transfer the ribs to the sheet, dabbing some sauce from the slow cooker on the meat. Broil until the ribs are brown and crusty on top, 3 minutes. Flip them, dab the other side with sauce from the slow cooker, and broil until they’re brown and crusty on that side, 3 minutes. Repeat the dabbing and broiling one more time, and then remove the ribs from the broiler and dab them with a final layer of sauce. Serve with the remaining sauce from the slow cooker.
Tip: Skip bottled barbecue sauce and make your own: Combine 1 cup of ketchup, 2 tablespoons of brown sugar, 2 tablespoons of cider vinegar, 1 tablespoon of yellow mustard, 1 tablespoon of Worcestershire sauce, 1 teaspoon of smoked paprika, ¾ teaspoon of salt (preferably smoked), ½ teaspoon of garlic powder, ¼ teaspoon of onion powder, ¼ teaspoon of ground black pepper, and ⅛ to ¼ teaspoon of cayenne in a small saucepan. Bring the mixture to a boil; then reduce the heat to low and simmer for 20 minutes. Cool, cover, and refrigerate the sauce for up to a month. Makes 1½ cups.