Allow the ham to sit at room temperature for 30 minutes before cooking. This will keep it from being cold in the center.
Preheat the oven to 325°F/160°C with the oven rack in the lower third of the oven, and line the roasting pan with foil.
To prepare the glaze, combine the honey, brown sugar, butter, mustard, cinnamon, cloves, ginger, and garlic powder in a small bowl.
Place the ham in the roasting pan cut side down, and brush with half of the glaze (use a pastry brush). Reserve half of the glaze for later.
Cover tightly with foil, and bake for 1-2 hours depending on the size of your ham. You need to bake for about 12 minutes per pound.
15 minutes before the ham is done, remove from the oven, and adjust oven temperature to 425°F.
Uncover, brush the rest of the glaze and put the ham back in the oven for about 10-15 more minutes or until a nice caramelized crust forms and the ham reaches 140°F/60°C internal temperature which is the safe temp to eat.
To get an extra brown and crispy crust, turn on the broiler and broil for 1-5 minutes to crisp up the top.
Allow the ham to rest on a platter for 15 minutes before serving. Waiting allows the sugar glaze to harden.