Cooking a Smithfield spiral ham is quite easy and the process can be quite rewarding. First, preheat the oven to 275 degrees Fahrenheit and remove all packaging materials from the ham. Then, place the ham (cut side down) on a large piece of aluminum foil in a roasting pan. Bake it for about 12-15 minutes per pound. Lastly, during the last 10 minutes of baking, brush the ham with a glaze of your choice for that extra flavor punch.