Be sure your turkey is fully defrosted before cooking. Preheat oven to 325° F.
Remove the turkey from the fridge and remove the packaging. Take out any giblets that were stored inside the turkey. Rinse the inside and outside of the turkey then pat dry. Place on the roasting rack of the pan and set aside for 30 minutes to 1 hour.
Just before putting it in the oven:Melt the butter with garlic powder and salt. Using a basting brush, brush the butter mix all over the turkey.Sprinkle the rosemary all over the turkey.
Add a cup of water to the bottom of the pan. Cover the turkey loosely with foil and place it in the oven. Be sure to put it in the center of the oven. Cook until about an hour before you estimated cook time
Remove the foil and continue cooking until the thickest part of the thigh (make sure you are not on the bone) reaches 165.
Your cook times:In conventional oven - it will be about 15 minutes per pound.In convection oven - it will be about 10 minutes per pound.
Once it is up to temperature, remove from oven and allow it to sit for about 30 minutes before carving.
Notes
Nutritional values and serving sizes are estimated. For the values it was based on an 18 pound turkey with 12 servings.We use unsalted butter but if you use salted you may want to reduce the amount of salt you use to one eighth.You can substitute oil for butter if you choose. I do not baste my turkey but some people recommend it. If you are going to baste it, I would do it when you have the door open to check if it is done.I don't recommend stuffing a turkey for safety reasons and this recipe is for roasting an unstuffed turkey.Cook times are estimated, be sure it is up to 165 in the thickest part of the thigh.