Preheat oven to 325 degrees F.
In a pan of a roasting rack, add about 2 cups of orange juice (cover about 3/4 inches of pan)1 and orange slices from 1 orange. Place foil over the rack and place ham on top. Seal roasting pan tightly with aluminum foil, and bake for about 1 to 1 ½ hours (about 10 minutes per pound), until the center registers 110 degrees F.
Make the glaze: in a saucepan, combine all ingredients and stir until it boils. Simmer for 10 minutes, until thickened. If too thick, add more orange juice. I you want it sweeter, add 1 to 2 more tablespoons brown sugar. Reserve half for serving.
Carefully, remove foil. Increase temperature to 400 degrees F. Baste with juices from the pan and brush with glaze, and then bake for 10 minutes, uncovered. Then, baste and brush with glaze and bake again for another ten minutes, until internal temperature reaches 140 degrees F.
Brush with glaze one more time, and broil for about 3-5 minutes, until fully caramelized and browned.
Remove from oven and let sit for 15 minutes before serving. Enjoy!