Put the chicken wings in a pan and cover with 1 litre cola. Add the bay leaves and allspice berries. Cover and gently simmer for 20 mins. Heat oven to 180C/160C fan/gas 4. Drain the wings and pat dry. Transfer to a roasting tin and toss with the oil, then cook for 20 mins. Meanwhile, put the remaining cola, the soy sauce, ketchup, sugar and mustard in a pan and bubble until you have a thick glaze. Paint the glaze over the chicken and return to the oven for another 15-20 mins, brushing with more glaze at 5 min intervals.