Preheat oven to 325 degrees.
Using a paring knife, score the fat of the ham creating the 1-inch diamond pattern. Stud the diamonds with the whole cloves.
Coat the bottom of a heavy-bottom roasting pan with olive oil. Put onion slices and orange quarters in the bottom. Place the ham on the onion and oranges. Place in pre-heated oven and roast the ham, uncovered, for about 20 minutes per pound, or until a meat thermometer reads 140 F.
In a small sauce pan, whisk together maple syrup, brown sugar, whiskey, mustard, orange juice, orange zest, ground cloves, and allspice. Heat over medium heat for 15 to 20 minutes until slightly thickened.
About 30 minutes before the end of the cooking time, brush the ham with the glaze. Once meat reaches 140 F internal temperature, remove from oven. Lightly tent with foil and allow to stand for 10 to 15 minutes before slicing. Serve hot.