- Heat oven to 150℃ /fan 130℃. Combine the dry-rub ingredients in a small bowl. Arrange the rib racks in a single layer on a large chopping board or clean kitchen counter.
- Season the ribs with the dry-rub on both sides, patting it down into all the nooks and crannies. Double wrap the racks individually, first in greaseproof paper then in foil; seal into a tight parcel. Arrange the rib parcels in a single layer on one (or two) baking sheets and bake until the ribs are very tender but not quite falling apart, 2 ½ hours. Remove from the oven.
- Switch your oven to its grill setting on high. Line a large baking sheet with foil. Carefully unwrap the ribs. Using tongs, carefully transfer the rib racks to the foil-lined baking sheet, leaving the juices behind.
- Baste the ribs on both sides with a third of the spicy bbq sauce. Grill for 5 minutes, turning once halfway through.
- Baste the ribs on both sides with the second third of the spicy bbq sauce and grill, turning once halfway through, for a further 5 minutes.
- Finally, baste the ribs on both sides with the remaining spicy bbq sauce and grill, turning once halfway through, for a final 5 minutes, or until lacquered and starting to crisp. Transfer to a platter and serve.