Place chicken breasts in a 9×13 inch baking dish. In a small bowl combine the ginger, soy sauce, onion flakes, sugar, bourbon & garlic powder. Mix together & pour mixture over the chicken. Cover the dish & place in the refrigerator. Marinate overnight.
Preheat oven to 325 degrees F.
Remove the dish from the refrigerator & remove the cover. Bake in the preheated oven, basting frequently, for 1 1/2 hours or until the chicken is well browned & juices run clear.