Carefully remove the membrane from the underside of the ribs using a small, sharp kitchen knife. Lift a corner and slide the knife underneath to loosen it. Once started, pull the membrane away with your fingers. I always wear disposable gloves when handling raw meat for safety.

In a small bowl, combine the brown sugar, kosher salt, paprika, onion powder, black pepper, and cumin. Stir well until fully mixed.

Spread two-thirds of the rub on the meaty side of the ribs, and the remaining third on the underside where you removed the membrane.

Spray a 6–7 quart slow cooker with nonstick cooking spray.

Spread 1 cup of BBQ sauce over the meaty side of the ribs using a spoon or basting brush.

Place the ribs inside the slow cooker with the meaty side against the sides.

Spread ½ cup of BBQ sauce on the inside of the ribs.

Pour ½ cup over the top ridge of the ribs. Save the remaining ½ cup for broiling later.

Cover with the lid and cook on low for 5 hours.

Preheat the oven to broil near the end of the slow cooking. Line a baking sheet with heavy-duty aluminum foil and spray with nonstick cooking spray.

Using tongs or a spatula, carefully transfer the ribs from the slow cooker to the baking sheet. The ribs will be extremely tender, so transfer in sections if needed.

Baste with the remaining BBQ sauce and broil for 2–3 minutes, watching carefully until the sauce bubbles and caramelizes. Serve hot.