Dry Chicken: Take the chicken out of its packaging and dry it with paper towels. Remove any giblets from the inside. Trim off any extra fat or loose skin if needed.
Spatchcock the Chicken: Place the chicken breast side down with the legs facing you. Use kitchen shears to cut along both side of the backbone from tail to neck. Remove the backbone (you can keep it for chicken stock). Flip the chicken over, breast side up, and press down firmly to flatten it. Tuck the wings under the chicken to keep them from burning. Watch this video for how to spatchcock a turkey.
Dry Brine the Chicken: Sprinkle kosher salt all over the chicken. Hold the salt about 6 inches above to spread it evenly. Place the chicken on a rack in a pan and put it in the fridge for 3 to 24 hours. Letting the chicken rest helps dry out the skin which is necessary to make it crispy.
Preheat the Pellet Grill: Fill the pellet smoker with hickory pellets and set it to 225°F.
Season the Chicken: Take the chicken out of the fridge and let it sit at room temperature. Rub the chicken with avocado oil until fully coated. Then cover it generously with pepper, granulated garlic, and granulated onion.
Smoke the Chicken: Smoke the chicken at a lower temperature such as 225°F. When the breast reaches an internal temperature of 140°F, baste it with melted butter. Then raise the smoker temperature to 300°F and continue cooking. Use a meat thermometer to check the chicken. It’s done when the breast reaches 155°F and the thighs reach 165°F, which should take about 2.5 to 3 hours.
Note: Take the chicken off the smoker just before it hits the target temperature. The heat will keep cooking it while it rests, bringing it up to the right temperature (165°F in the breast and 175°F in the thighs).
Rest and Serve: Let the chicken rest for 10-15 minutes before carving. This helps the juices stay inside the meat, making it juicier and more flavorful.
Notes
If you don't have a fancy Traeger smoker, you can cook spatchcock chicken on a charcoal grill:
First, light your charcoal and set it up for indirect heat by pushing the coals to one side of the grill. This way, the chicken will cook slowly without direct flames underneath. Place a drip pan on the other side of the grill to catch any juices.
Put the chicken on the grill with the breast side up, over the side without the coals, and cover the grill. Make sure the temperature stays around 225°F to 250°F. Add some wood chips or chunks to the coals for smoke, and let the chicken cook slowly for a couple of hours, checking the temperature with a meat thermometer.
When the chicken reaches 165°F in the breast and 175°F in the thighs, it’s ready to take off the grill and rest before serving.