Position oven rack in bottom third of oven. Preheat oven to 325°F.
Remove 1 teaspoon orange peel and 1 teaspoon lemon peel from fruit. Cut peeled orange and peeled lemon into quarters; set aside.
Combine orange peel, lemon peel, butter, minced rosemary, 1 teaspoon salt, 1 teaspoon pepper, onion powder and garlic powder in medium bowl.
Drain juices from turkey and pat dry with paper towels. Place turkey, breast side up, on flat rack in a shallow roasting pan (2 to 2½ inches deep). Evenly spread ¼ cup butter mixture between skin and breast meat of turkey, being careful not to tear the skin.
Season cavity of the turkey with remaining 1 teaspoon salt and 1 teaspoon pepper. Place peeled orange and lemon quarters, 2 shallots and rosemary sprigs into turkey cavity. Tie legs together with kitchen string. Turn wings back to hold neck skin in place. (Tucking wings will help stabilize turkey in the pan and when carving). Rub ¼ cup butter mixture all over turkey. Cut the remaining 2 oranges and 1 lemon into quarters. Place orange and lemon quarters and the remaining 4 shallots around the turkey. Insert an oven-safe meat thermometer deep into the lower part of the thigh without touching bone.
Melt remaining ½ cup butter mixture and keep warm.
Bake turkey until meat thermometer in thigh registers 180°F and an instant-read thermometer inserted into breast and stuffing registers 170°F (3 to 3 ½ hours brushing turkey with melted butter mixture once every hour for the first 2 hours and covering loosely with foil after 2 hours to prevent excess browning). Lift turkey onto a platter and let stand 15 minutes before carving.