Heat oven to 425° F.
Place the carrots, onion, giblets (if included), and 1 cup water in a large roasting pan and top with a roasting rack. Rub the turkey with the oil and season with 2 teaspoons salt and 1 teaspoon pepper. (Be sure to season inside the cavity, too.) Tie the legs together with twine and tuck the wings underneath the body.
Roast until the turkey is golden brown and the skin is beginning to crisp, 45 minutes to 1 hour. Reduce oven temperature to 325° F. Continue to roast the turkey and begin to baste with the butter baste ( Molasses and Bourbon, Smoked Paprika, or Chili, Garlic, and Rosemary) every 30 minutes, until an instant-read thermometer inserted in the thickest part of a thigh registers 165° F, 1 hour, 15 minutes to 1 hour, 40 minutes more. (Add 1 cup more water to the pan if the vegetables begin to scorch.)
Carefully tilt the turkey to empty the juices from the cavity into the roasting pan. Transfer the turkey to a cutting board and let rest for at least 30 minutes and up to 1 hour before carving. Reserve the pan and its contents for Ultimate Gravy.