Combine salt, white sugar, brown sugar, black pepper, white pepper, onion powder, garlic powder, chili powder, paprika, and cumin in a bowl to make the rub.
Generously coat the ribs with this spice blend, wrap them in plastic, and refrigerate for at least 30 minutes.
Meanwhile, mix apple juice, brown sugar, and barbeque sauce to make your basting sauce.
Remove the ribs from the fridge and place them in a single layer on the smoker’s wire racks.
Load the smoker pan with apple, grape, pear, or cherry wood chips, then heat it to 270°F (130°C).
Smoke the ribs for an hour, then begin basting them with the prepared sauce every 30 to 40 minutes.
Continue cooking until the meat shrinks back from the bones and is no longer pink, about 3 to 4 hours in total.
Brush on one final layer of sauce, remove the ribs, and wrap them tightly in foil.
Let them rest for 10 to 15 minutes so the juices can reabsorb before serving.