Prep the meat. Remove the membrane from the bone side of the ribs for tender results. To do this, use a sharp knife to loosen the edge of the membrane, then grip it with a paper towel and pull firmly. Then, rub both sides of the ribs generously with your favorite dry rub or seasoning blend. Next, cut the ribs into sections of 2–3 ribs each for easier handling using kitchen shears or a sharp knife.
Cook in the slow cooker. Place the rib sections in your slow cooker. Then, pour the can of Dr. Pepper and add the liquid smoke, making sure the ribs are submerged as much as possible. Cover and cook on LOW for 8–10 hours (for fall-off-the-bone ribs) or HIGH for 4–5 hours (for a quicker cook). For best results, the low setting is recommended.
Broil to finish. Preheat your broiler. Line a rimmed baking sheet with aluminum foil for easy cleanup. Then, carefully transfer the ribs from the slow cooker to the prepared baking sheet, placing them meaty side up. Brush a generous layer of barbecue sauce over the ribs, making sure they are evenly coated. Broil for 1–2 minutes until the sauce is bubbly, caramelized, and slightly browned. Keep a close eye to prevent burning!
Serve and enjoy. Serve the ribs hot with extra barbecue sauce on the side for dipping. Pair with your favorite sides like coleslaw, cornbread, or baked beans for a crowd-pleasing meal.