Preheat the oven to 325°F. Score the surface of the ham with shallow diagonal cuts, dot with the cloves, and place in a roasting pan.
Combine ½ cup pineapple juice, ½ cup maraschino cherry juice, and the brown sugar in a saucepan and bring to a simmer. Let simmer until thickened, about 5 minutes. Baste the ham with the pineapple cherry sauce, cover with foil, and roast for 1½ hours, basting every 30 minutes.
Remove from the oven and decorate with the pineapple slices and as many cherries as you’d like, securing with toothpicks. Baste again and cook uncovered for another 30-45 minutes. Remove the cloves before serving.