Remove any excess from the ham as needed, then set it inside a slow cooker.
Combine the melted butter and honey in a small bowl, then apply the blend all over the ham, working it into the cuts. Put the lid on and cook on low for 4 to 5 hours.
Near the end of the cooking period, turn on the oven broiler to high and cover a roasting pan with foil.
Mix the brown sugar, garlic powder, cinnamon, nutmeg, cloves, paprika, and salt together in a small bowl. Firmly press half of this blend onto the top of the ham.
Broil until it bubbles and caramelizes, about 3 minutes, then take it out of the oven.
Transfer the remaining sugar mixture into a small saucepan and set it over medium heat. Pour in 3 tablespoons of the ham liquid from the slow cooker (or water). Bring to a boil, stirring occasionally.
Boil for 1 minute, then take it off the heat. Coat the ham with the glaze, then broil again briefly, just 1 to 2 minutes.
Allow the ham to rest at least 5 minutes before serving. Enjoy!