Combine the garlic powder, salt and pepper. With fingers, carefully loosen skin from the turkey breast; spread half of garlic powder mixture under the skin. Sprinkle skin with remaining mixture. Juice the orange, reserving the rind. In a large bowl, combine the cranberry sauce, teriyaki sauce, honey, marmalade, soy sauce and orange juice. Cover and refrigerate 3 1/2 cups mixture for sauce. Rub remaining mixture under the skin. Secure skin to underside of breast with toothpicks. Place herb sprigs and reserved orange rind in turkey cavity. Arrange onions in a shallow roasting pan coated with cooking spray. Place turkey over onions. Bake, uncovered, at 325° for 3 to 3 1/2 hours or until a meat thermometer reads 180°. (Cover loosely with foil if turkey browns too quickly.) Cover and let stand for 15 minutes before carving. Discard herb sprigs and orange before slicing. Place reserved sauce in a large saucepan; heat through. Serve with turkey. Yield: 28 servings (3 1/2 cups sauce).