Carve each chicken into 8 pieces.
Chop scallions and garlic into small pieces. Stir through with sugar, five-spice soy sauce, fish sauce, powder, chili sauce and salt in a bowl.
Arrange chicken pieces in a shallow porcelain bowl and spoon marinade over. Turn chicken pieces all around in the marinade to the other side. Cover and refrigerate for one night. Preheat the stove to 210 degrees. Coat a baking tray with oil, arrange the chicken pieces on it and bake for 45-50 min until crispy.
Serve warm with lime wedges.