• Combine all the spice rub ingredients together in a small bowl. Using paper towels, pat the ribs dry and then cover both sides with the spice rub. Be sure to massage the spices into the meaty side of the ribs. Cut the rack(s) in half and place them in the slow-cooker vertically with the thick ends pointing down and the meaty side against the interior wall of the slow-cooker. If the ribs are too tall to fit against the wall, tilt them toward the sides of the slow-cooker. Ribs may overlap, this is okay. Cover and cook until ribs are just tender and the meat is pulling away from the bones, about 5 or 6 hours on high or 6 or 7 hours on low.
• Using two sets of tongs carefully remove the ribs to a baking sheet (meaty side up) and allow them to rest about ten minutes.

To grill the ribs:

• While the ribs are resting, preheat the grill on high. Using two sets of tongs transfer ribs to the grill with the meaty side facing up. While the bottom of the ribs char, cover the top meaty part with the barbecue sauce. After five minutes, carefully turn the ribs with the sauce side facing down. Brush sauce on the other side. Grill the ribs, turning one more time adding more sauce until the ribs are well charred and the sauce is caramelized, about 10 - 15 minutes. Remove from the grill, tent with foil and allow ribs to rest for 15 minutes. Cut ribs in between the bones to separate. Serve with remaining sauce.

To broil the ribs:

• Line a rimmed baking sheet with aluminum foil and place a wire rack inside the baking sheet. Adjust the oven rack 3 inches from the broiler element and heat on high. Place the ribs on the rack, meaty side up. Brush the ribs with barbecue sauce and broil until the sauce is bubbling and starting to char, about 5 minutes. Remove the ribs from the oven and brush with additional sauce. Tent with foil and let rest for 15 minutes. Cut ribs in between the bones to separate. Serve.