1teaspoon ground nutmeg (freshly ground, if possible)
1/2teaspoon ground ginger
1/2teaspoon ground cloves
8pound bone-in spiral-sliced precooked ham
In a small bowl, combine the sugar, onion powder, cinnamon, nutmeg, ginger, cloves, and paprika. Mix the seasoned sugar mixture well. Cover a baking sheet with aluminum foil; if you fail to do this, you may have burnt sugar on your pan, and it will take a while to clean off.
Place the ham open meat side down onto the pan. Sprinkle with the seasoned sugar mixture. Press the sugar onto the outside of the ham. You may not use all of the seasoned sugar mixture. With a blowtorch, gently heat the seasoned sugar mixture on the ham. Wave the flame quickly over the sugar—you want the sugar to brown, not burn.
Staying in one area, and moving out from there slowly will make this easier, as you will be heating the sugar in a continual direction. This whole process will take about 15 minutes, so be patient. You can sprinkle more sugar on top of the already browned parts of the ham and make the crust thicker. You can either reheat the ham or serve it cold when you are finished.