Grease the inside of a slow cooker with non-stick spray or butter. Place the ham inside, cut side down. If needed, trim excess fat from the surface.
In a bowl, combine the jar of Pineapple Bourbon Ham Glaze, ¼ cup of the juice from the can of pineapple, brown sugar, honey, Dijon mustard, cinnamon and cloves (if using). Whisk until smooth.
Carefully pour the glaze evenly over the ham, making sure it coats the surface well. Situate the pineapple slices on top of the ham and secure with a toothpick.
Cover and cook on low for 5-6 hours or on high for 2-3 hours. Baste the glaze over the ham every 45-60 minutes.
Remove the ham from the slow cooker once it’s heated through. Carefully pour the liquid from the slow cooker into a saucepan and bring it to a gentle simmer over medium heat. Mix cornstarch with 2 tablespoon water to make a slurry, then whisk it into the simmering liquid. Cook for a few minutes until the glaze has thickened to your desired consistency.
Arrange the sliced ham on a serving platter. Drizzle the thickened pineapple glaze on top and garnish with fresh parsley, if desired.
