Set your oven to 325°F (165°C) and position the rack in the middle.
Remove the plastic button or disc from the bottom of the ham and place it flat side down in a large baking dish or roasting pan. Cover tightly with foil.
Bake the ham for 12-15 minutes per pound. Most spiral hams should take no longer than 90 minutes to reach an internal temperature of 140°F (60°C). Use an oven-safe thermometer for accurate readings.
In a saucepan, combine Dijon mustard, orange juice, brown sugar, honey, soy sauce, cinnamon, and cloves. Bring to a boil, then reduce heat and simmer. For a thicker glaze, add a slurry of cornstarch and water (1 part cornstarch to 2 parts water). Remove from heat and let cool.
Once the ham reaches an internal temperature of 140°F (60°C), remove it from the oven. Turn the oven temperature up to 425°F (220°C). Baste the ham with half of the glaze, ensuring it penetrates between the layers. Return the ham to the oven, uncovered, and bake for 15-20 more minutes, or until the ham is browned and the glaze is caramelized.
Serve: Slice the ham and serve on a platter with the remaining glaze on the side.