Place the ham in the basin of a slow cooker.
In a small saucepan, combine the brown sugar, Coca-Cola, Dijon mustard, apple cider vinegar, and ground cloves. Bring to a boil over high heat, stirring until the sugar is fully dissolved.
Pour the glaze over the ham. If the ham is pre-sliced, spoon some of the glaze in between the slices.
Cover and cook on LOW for 6–8 hours or HIGH for 4–6 hours, basting with the cooking juices every few hours.
Remove the ham from the slow cooker and let it cool slightly until it can be handled. Slice and serve.
Optional: For a caramelized finish, preheat the broiler. Transfer the ham to an oven-safe dish, brush with some of the leftover liquid, and broil for about 5 minutes, glazing once more if desired.