1.Whisk vinegar, oil, molasses, salt, chilli, cayenne pepper and water in a large jug until combined; reserve ½ cup marinade.
2.Combine remaining marinade with ribs in a large shallow dish. Cover and refrigerate 3 hours or overnight.
3.Heat covered barbecue to 180°C. Place ribs in disposable baking dish. Cook, using indirect heat, following manufacturer’s instructions, about 35 minutes. Brush with some of the reserved marinade; cook a further 15 minutes, brushing ribs with remaining marinade every 5 minutes.
4.Remove ribs from barbecue; cover, stand 5 minutes. Cut into individual ribs to serve.
Treacle can be used in place of molasses.Note