For the marinade, combine 1 cup dark soy sauce, 1 tsps rock sugar or brown sugar, 1 tsp five-spice powder, ginger and the chopped scallions. Place the chicken in a large bag and add half the marinade. Reserve the remaining half of the marinade to baste the chicken during cooking. Marinate the chicken in the refrigerator for at least 4 hours (preferably overnight) turning the bag occasionally (when you are not sleeping) so that all the chicken is coated Preheat the oven to 450 degrees F. Place the chicken on a rack in a roasting pan. Roast for 15 minutes. Reduce the heat to 375 degrees F. Roast the chicken, basting frequently with the reserved marinade, for another hour or until it is cooked. (To check for doneness, pierce the chicken in the thickest part of the thigh. The juices should run clear. If using a meat thermometer, the temperature should read 170 degrees F. in the thickest part of the thigh.Let the roasted chicken sit for 15 minutes before serving.