Using a sharp knife make 1" cuts in a diamond pattern - no more than 1/4" deep.
Place ham in roasting pan.* Tent with foil. Bake for 1 hour and 30 minutes.
In a saucepan, whisk together all of the ingredients over medium heat until sugar dissolves. Remove from heat and let cool.
After cooking the ham, remove the foil and brush a quarter of the glaze on. Bake uncovered for 10 minutes. Repeat 3 more times until all the glazed has been used (a total of 40 minutes).
Notes
*To have an easier clean up place a piece of aluminum foil underneath the roasting rack to prevent the glaze from sticking to the roasting pan.