Make the glaze: stir all glaze ingredients together in a bowl until blended; set aside (can be made ahead of time and stored in airtight container in the refrigerator for up to two weeks).
Preheat oven to 300°; line a large roasting pan with foil or a silicone baking liner.
Remove ham from its packaging and drain off any juices.
Place ham in prepared pan, flat side down, making sure to remove the little plastic disk covering the bone, and cover the ham and pan completely with foil.
Bake until an instant-read thermometer inserted in the center reads 120°, about 2 ½ hours.
Increase oven temperature to 400° and remove the foil covering from the pan.
Pour the glaze over the ham and bake uncovered, basting every 10 minutes with the pan juices, until the glaze is set, another 20-30 minutes.
Remove the ham from the oven and let it rest for 15 minutes before carving.
Serve the ham drizzled with any remaining glaze/pan drippings.