Preheat oven to package directions (approx 350 degrees). Line a dutch oven with aluminum foil to wrap your ham. Place the ham cut side down in the dutch oven. Wrap the ham with foil and cover with a lid. Bake according to package directions for HALF the time.
While the ham is heating, in a medium sauce pan, stir together all other ingredients. (Use all of the zest + juice of the orange.)
Heat over medium heat, stirring frequently, until the sugar has dissolved. Bring to a low boil, stirring. Reduce heat to a simmer until thickened to desired consistency, about 30 minutes.
When the ham has heated half the package time, remove from the oven. remove lid and pull back the foil. Generously brush the ham all over with the cranberry sauce. Place back in the oven uncovered for 15 minutes.
Repeat this process, basting and baking, for 2 - 3 more times until the ham is heated through and the cranberry glaze is rich and thick.
Remove from heat, let rest for 15 minutes. Slice and serve with additional cranberry glaze.