1 9-to-10-pound bone-in fully cooked smoked ham (butt or shank half)
2 tablespoons whole cloves (optional)
For the glaze:
2 cups apple cider
1/4 cup whole-grain mustard
1/2 teaspoon allspice
1/4 teaspoon nutmeg
Boil 2 cups apple cider in a saucepan over medium-high heat until reduced to 1/2 cup, 8 to 10 minutes. Reduce the heat to low; add 1/2 cup each apple jelly and maple syrup, 1/4 cup whole-grain mustard, 1/2 teaspoon allspice and 1/4 teaspoon nutmeg.
Remove the ham from the refrigerator and bring to room temperature, about 30 minutes.
Preheat the oven to 325 degrees F (162°C) . Trim off any skin from the ham. Use a sharp paring knife to score through the fat in a diagonal crosshatch pattern without cutting through to the meat. Insert the cloves into the ham (if using), placing them at the intersections of the cuts.
Put the ham, flat-side down, on a rack in a roasting pan. Pour 1/4 inch water into the bottom of the pan. Transfer to the oven and roast until a thermometer inserted into the thickest part of the ham registers 130 degrees F, about 2 hours, 30 minutes (about 15 minutes per pound).
Increase the oven temperature to 425 degrees F (220°C) Pour half of the glaze over the ham and brush to coat. If the water in the bottom of the pan has evaporated, add more. Return the ham to the oven and roast, basting every 10 minutes with the remaining glaze, until glossy and well browned, about 45 more minutes.