Preheat smoker to 225 degrees F. Remove pre-cooked ham from packaging. Rinse and pat dry with a paper towel. If your ham is not spiral-cut, score the outside. This will help the glaze to sink into the meat. Score the ham with a knife, and cut long cuts from the top of the ham down to the bottom. Next, make a second set of perpendicular cuts to form a diamond pattern all over the outside, about ¼-inch deep, 1½-inches apart.
Place the ham cut side down in an aluminum pan. Brush the exterior of the ham with olive oil and apply a spice rub, covering the exterior. Add orange juice to the pan. Close the lid and smoke the ham, uncovered, for about 2 hours, until the meat reaches an internal temperature of 130° to 135°F.
When your ham is near the correct internal temperature, prepare your glaze. Combine all glaze ingredients in a small saucepan over medium heat, stirring occasionally. Bring it to a boil and turn off the heat. Reserve ½ cup to ¾ cup of the glaze to serve with the ham.
After the meat reaches that 130° to 135°F internal temperature, brush on the glaze and coat the ham on all sides. Re-apply the glaze every 30 minutes and continue smoking until you reach an internal temperature of 140°F, about 1 more hour.
Once your ham has reached an internal temperature of 140°F, the exterior should be nice and caramelized. Remove the ham from the smoker, tent it with foil, and let it rest for 10 minutes. Spoon leftover glaze over top of the ham for a stunning presentation before you slice it and serve, or serve reserved glaze alongside the ham for extra sauce.