Place chicken and dressing in a large ziplock bag, massage gently to evenly coat. Place in the fridge to marinate for at least 30 minutes or up to 2 hours.
Preheat pellet grill smoker to 300F. Place the marinated chicken directly on the grill grates and smoke for 30 minutes. Flip chicken and smoke for an additional 30 minutes, or until the internal temperature of the thickest part of the meat reaches 165F. (Use an instant-read thermometer to check!)
Remove the chicken from the smoker, tent with foil for at least 10 minutes, then slice or serve.