Preheat the oven to 325°F (165°C)
Remove the ham from packaging
Place the ham cut-side down in a roasting pan
Score the surface of the ham in a diamond pattern, if desired
Add a small amount of water to the bottom of the pan
Cover the ham tightly with foil
Bake until heated through, about 10 to 15 minutes per pound
Remove the foil during the last 20 to 30 minutes, if glazing
Brush on glaze during the last 20 to 30 minutes, if using
Bake uncovered until the glaze is set and the ham reaches 140°F (60°C) for fully cooked ham
Bake until the ham reaches 145°F (63°C) for uncooked ham
Remove from the oven
Let the ham rest for 10 to 15 minutes before slicing
Slice and serve