Combine all the ingredients together for the coffee rub and set aside.
For the burgers soak the bread in the milk for 10 minutes. Squeeze out the bread and add to the mince and discard the milk. Add the onion, seasoning and Worcestershire sauce. Mix through and shape into 6 large burger patties.
Coat each burger in coffee rub and preheat the grill. Grill the burgers for 5-7 minutes on one side and turn and grill on the other side.
Serve on hamburger rolls garnished with lettuce, tomato, onions slices and a dollop of barbecue sauce.