Start by spatchcocking the chicken. Place it with the spine facing upwards. Get a good pair of kitchen shears and start cutting lengthwise along the right side of the spine. Then do the same on the left side, effectively removing the entire backbone.
Save the backbone if you like, it is great for making chicken stock.
Now flip the bird over and press gently with your hand to flatten the bird a bit. Turn/rotate the chicken thighs if needed so they lay flat also.
Apply 0.5 tbsp of the rub evenly on the chicken skin.
Fire up the grill/smoker and have it running at 150° C / 300° F. We're cooking at slightly higher temps to make sure the skin is crispy. If cooked at lower temps it tends to get rubbery.
Place the chicken in the grill/smoker and leave it for 20 minutes.
In the meantime: melt the butter and mix it with 1 tbsp of the rub. Stir well.
Now it's time for the first baste: use a brush and brush liberal amounts of the butter rub all over the chicken, then put it back in the smoker.
Repeat the basting after another 20 minutes have passed.
The chicken is done when the internal temp is 70° C / 158° F. Check both chicken breasts as well as the thighs to make sure it's safe. Serve it with a tasty Alabama White Sauce.