Heat oven to 275 degrees.
Wrap ham completely in heavy duty aluminum foil and place in a roasting pan.
If ham is not sliced, use a knife to cut a crosshatch pattern, only going about 1/4-inch deep. This will help keep the glaze on the ham.
Bake for about 2 1/2 hours. The ham is already fully cooked, but you want it to reach an internal temperature of 120 degrees.
Combine all ingredients for glaze in a medium bowl and mix well.
Remove ham from oven and raise oven temp to 400 degrees.
Brush glaze all over ham, being sure to get a little between the slices.
Place ham back in oven for 10 minutes. You can keep it loosely wrapped in foil or pull the foil down and away from the ham.
Remove ham from oven, baste again and place ham under broiler for a few minutes to get glaze golden brown.