To cook a spiral ham in the oven, follow these guidelines:

• Preheat the oven to 325°F (163°C) for a standard bake or 275°F (135°C) for a slower, low-and-slow cook to keep the ham moist.
• Spiral hams are usually pre-cooked, so you are just reheating them. Heat the ham for about 12 to 15 minutes per pound.
• Use a meat thermometer to ensure the internal temperature reaches 140°F (60°C) for safe serving.
• Cover the ham with foil to prevent drying out during most of the cooking time.
• If applying a glaze, add it during the last 20 minutes of cooking and remove the foil to allow the glaze to caramelize.
• Let the ham rest for at least 15 minutes after removing it from the oven before slicing.

For example, an 8 to 10-pound spiral ham will take roughly 1.5 to 2.5 hours at 325°F, depending on size and whether covered or uncovered

. Summary:

• Oven temp: 275°F (slow) or 325°F (standard)
• Time: 12-15 minutes per pound
• Internal temp: 140°F
• Covered with foil until glazing stage
• Glaze applied last 20 minutes uncovered
• Rest 15 minutes before serving

This method ensures the ham is heated through without drying out and allows for a nicely caramelized glaze if desired