3 cups orange juice
1 1/3 cups light brown sugar
1 orange, zested
1 bay leaf
1 cinnamon stick
2 teaspoons whole black peppercorns
8 whole cloves
1/4 teaspoon ground allspice
1/4 cup plus 2 tablespoons dark rum
For the ham:
1 (8 to 10-pound) fresh ham, shank end, bone-in and skin-on
1 1/2 tablespoons kosher salt
1 1/2 tablespoons Essence, recipe follows
2 teaspoons freshly ground black pepper

Make the glaze by combining the orange juice, brown sugar, orange zest, bay leaf, cinnamon stick, peppercorns, cloves and allspice in a large saucepan and bring to a boil. Continue to cook at a brisk simmer until the mixture has reduced in volume to just over 1 cup and is thick enough to coat the back of a spoon, about 30 minutes. Remove from the heat, add the rum, and set aside to cool.

Remove the ham from the refrigerator and allow to come to room temperature for at least 30 minutes before baking. While the ham is still cold, using a sharp knife, score the skin of the ham, making a diamond-pattern through the skin and fat about 1/2-inch deep.

Preheat the oven to 450 degrees F.

Using your hands, rub the salt, Essence, and pepper evenly over the entire surface of the ham. Place the ham in a large roasting pan and bake, uncovered, for 1 hour, or until the scores begin to open up and the ham begins to color. Reduce the oven temperature to 325 degrees F and continue to cook the ham until an instant-read thermometer inserted into the thickest part of the ham registers 155 to 160 degrees F, 3 to 3 1/2 hours longer. The ham will continue to cook after removed from the oven.

During the last hour of cooking, baste the ham often with the glaze and any pan juices that have accumulated. The skin should be crisp and dark. If the skin threatens to burn before the ham is cooked through, cover the ham loosely with aluminum foil.

When the ham is ready, transfer it to a large platter or carving board and let sit for at least 20 minutes before carving. To serve, slice the meat thinly across the grain and arrange slices on a platter. Serve with any pan juices passed on the side.