Prepare the bird. To ensure that your frozen turkey cooks evenly, be sure to fully thaw it before using it. Take off the giblets and neck from the cavity, keeping the neck aside. Using paper towels, pat the turkey extremely dry all around, including within the cavity.

Stir in the dry brine. Mix the kosher salt, white pepper, brown sugar, and buttermilk powder in a small bowl until thoroughly blended.

Give the turkey a dry brine. Arrange the turkey, breast side up, on a foil or parchment-lined baking sheet with a rim. Apply the dry brine over the whole turkey, including the cavity and below. Carefully remove the skin off the meat, being sure to evenly distribute the dry brine below it. Store, uncovered, in the refrigerator for a minimum of 24 and a maximum of 48 hours.

Prepare to cook your bird. Take the turkey out of the refrigerator two hours before cooking.

Mix butter with herbs. Combine the two sticks of melted butter, minced garlic, thyme, sage, rosemary, lemon zest, and pepper in a small bowl. Apply butter to the entire turkey, including the underside. Place the chopped lemon, garlic head, sage, and rosemary into the turkey cavity. Tie the legs up if you'd like.

Set the cheesecloth aside. After folding the cheesecloth to a thickness of four sheets, cut it into a broad rectangle that will cover the entire turkey. The last stick of butter should be melted in a small microwave-safe basin. Make sure all of the melted butter has been absorbed by the cheesecloth by soaking it in it. Cover the entire turkey with it after spreading it out.

Turn the turkey over. Find the thickest area of the turkey thigh to insert a probe thermometer inside. With 1 1/2 cups of water in the bottom of the roasting pan, place the turkey on the rack. Bake for 2 1/2 to 3 1/2 hours, basting every 45 minutes or so, or until the thigh registers between 160 and 165 F. Place a tiny piece of foil over any region of the turkey that is too browned.

Slice and rest. Take out the cheesecloth and the bird from the oven. Before slicing, tent it with foil and let it rest for half an hour. To make gravy, set aside the roasting pan's bottom drippings.