Heat grill to 375-400 F.

Use kitchen shears or knife to remove backbone from chicken to lay flat. Remove rib cage, if desired, or push flat with hands.

Mix butter, heat-and-sweet seasoning and garlic powder. Using meat injector, inject mixture into chicken. Rub remaining buttered seasoning over chicken and season with salt and pepper, to taste.

Place spatchcock chicken breast-side up over indirect heat and cook 35-40 minutes.

When internal temperature reaches 145 F, flip chicken breast-side down over direct heat 5 minutes, or until internal temperature reaches 165 F.

Let rest 10 minutes before serving.