Preheat oven to 350°F. Line a large baking pan with heavy-duty aluminum foil. Place ham cut side down in center of pan.
Trim any rind or excess fat from ham with a sharp knife. Score outside of ham with a sharp knife in a decorative diamond pattern (as shown) and insert a whole clove into each diamond point. Cover pan and ham with more heavy-duty aluminum foil. Bake ham for 1 1/2 hours.
Make glaze: Melt orange marmalade in small saucepan over medium heat, stirring occasionally. Whisk in Dijon mustard and 2 Tbsp. water. Bring mixture to a boil and cook for about 10 minutes, until glaze thickens. Set glaze aside.
Remove ham from oven and raise oven temperature to 425°F. Remove aluminum foil covering ham and brush warm glaze all over ham. Return ham to oven and bake uncovered until glaze caramelizes, about 30 minutes. Remove ham from oven, tent loosely with aluminum foil to keep warm, and let stand for 30 minutes before serving.