Preheat oven to 325 degrees. In a large roasting pan, place spiral sliced ham. Pour one cup of apple cider vinegar on the top of ham and let it run down the sides. Using toothpicks, attach pineapple rings to the ham, save the juice from the pineapple. Place into oven.
Every 30 minutes, open the oven to pour another cup of vinegar over ham. This helps remove the "wild" taste of the meat and makes it more tender. Continue basting and roasting for a total of 2 hours.
While ham is roasting, combine orange juice, cloves, and leftover pineapple juice in a small saucepan. Bring to a low simmer. Combine cornstarch with a tablespoon of cold water and stir. While whisking the juice mixture vigorously, slowly pour in cornstarch mixture. Return pan to a simmer. The sauce should thicken. Remove from heat.
Remove ham from oven, and place on a carving board. Discard leftover ham juices and vinegar in the roasting pan, they cannot be used for gravy. Allow ham to rest for 30 minutes while reheating the sauce. Slice ham, serve with sauce. Enjoy!