Spiral-cut hams come fully cooked and with slices already started, which makes them a relatively quick and easy meal option. It also means you only bake them to heat them, not to cook them. Confirm on the packaging that the product you have is indeed fully cooked; if it's not, you'll need considerably more cooking time. Also, check the package directions for any special instructions specific to the size, style or flavoring of your particular spiral ham. For example, bone-in hams warm through faster than boneless cuts, and certain glazes are more prone to burning.
Position an oven rack one or two slots below the middle tier so that the spiral ham is approximately centered in the oven during baking. Preheat the oven to 350 degrees Fahrenheit.
Remove all packaging from the spiral ham. If the product your purchased has a packet of seasoning or glaze you need to apply, follow the instructions for use. If your spiral ham is unseasoned, apply seasonings or a glaze to taste, or according to the directions in a chosen recipe. Salt, pepper, rosemary and thyme are a nice combination, for example, and citrus or honey glazes are good complementary picks for spiral hams.
Place the spiral ham on the rack of a shallow roasting pan. Bake a fully cooked ham for about 10 minutes per pound, just until it's warmed through. Check periodically between the pre-made slices for warmth and to prevent them from drying out. Bake an uncooked ham for about 20 minutes per pound. Cooking times vary, though, depending on a number of factors; use a meat thermometer to verify safety when cooking an uncooked spiral ham. The center of the meat should reach 145 degrees.
Rest an uncooked spiral ham for three minutes before carving it so the juices can redistribute and settle.