To start off preheat your smoker to 225°F. For this recipe, I like to use an apple wood. It goes deliciously with the pork in this recipe.
Remove all the excess fat, silver skin (membrane) from the outside of the loin.
In a bowl mix together the ground cinnamon, nutmeg, white pepper, cumin, onion powder, paprika & salt. Rub the loin with olive oil and sprinkle over some of the dry rub.
Smoke the pork loin at 220°F for 3 hours. Basting as necessary. Check the internal temperature with a meat thermometer. You are looking for an internal temperature of 155°F.
If you have achieved an internal temperature of 155°F, transfer from the smoker to your platter and cover for at least 20 minutes before carving.
If an internal temperature of 155°F is not achieved put back in the smoker, checking every half hour and basting as necessary.