In the final 30 minutes of cooking time, make the BBQ sauce by combining all the ingredients in a small pan and bring to a simmer. Keep stirring until the sauce reduces to a thick glaze, then remove from the heat. To ensure the ribs are cooked through, use a meat thermometer to check that the internal temperature has reached 82C. For the final 5 minutes of cooking time, turn the ribs bone-side down and generously brush all over with the glaze. Once the glaze has darkened a little, remove the ribs and rest for 15 minutes. Slice the rack into individual ribs and serve alongside fries and coleslaw, if you like.