Source: Bon Appetit
1 (18 pound) fully cooked bone-in smoked ham, room temperature
48 whole cloves
4 cups water
1 cup orange marmalade
1/4 cup prepared cream style horseradish
1/4 cup (packed) golden brown sugar
2 cups fresh orange juice
Position rack in bottom third of oven and preheat to 325 degrees F.
Place ham on rack set in large roasting pan. Using sharp knife, score ham in diamond pattern. Press 1 clove into center of each diamond. Pour 4 cups water into roasting pan. Roast ham 1 hour and 30 minutes.
Meanwhile, blend marmalade, horseradish and sugar in medium bowl.
Remove ham from oven. Transfer ham to baking sheet. Discard pan juices. Return ham to roasting pan. Add orange juice to roasting pan. Brush top of ham with 1/3 of marmalade glaze. Bake ham 10 minutes. Baste with orange juice in pan, then brush with half the remaining marmalade glaze. Bake ham 10 minutes. Baste with juices from pan, then brush with remaining glaze. Roast ham until heated through, basting every 5 minutes, about 20 minutes longer. Let ham rest 15 minutes. Transfer to platter.
Serve ham hot, warm, or at room temperature.