Preheat your smoker to 250 degrees F. Use applewood or hickory wood chips for best flavor.

In a small bowl, mix together the dark brown sugar, chili powder, smoked paprika, onion powder, garlic powder, dried oregano, and salt.

Pat the chicken dry with paper towels. Rub the spice mixture all over the chicken, making sure to get under the skin where possible.

Place the chicken in the smoker. Smoke for 3.5 to 4 hours, or until the internal temperature reaches 165 degrees F in the thickest part of the thigh.

Remove the chicken from the smoker and let it rest for 10 minutes before carving.