Preheat a smoker drum to 300 degrees F (150 degrees C). Preheat a charcoal grill to 600 degrees F (315 degrees C).
Combine the all-purpose and beef rub in a small bowl. Apply the rub mixture to both sides of the steak and let it rest at room temperature until the meat begins to sweat, this takes about 30 minutes.
Sprinkle the steak with garlic powder, onion powder, and black pepper.
Place the steak on the smoker and cook until an internal temperature of 100 to 110 degrees F (38 to 43 degrees C), 15 to 25 minutes.
Transfer the steak from the smoker to the grill, spraying it with oil. Cover and cook for 1 minute. Flip the steak and cook for an additional minute, to achieve the desired grill marks.
Return the steak to the smoker and continue to cook until it reaches an internal temperature of 135 degrees F (57 degrees C), an additional 10 to 15 minutes.
Pull the steak from the smoker and baste it with melted butter. Let the steak rest for 5 to 10 minutes. Slice the steak and dust it with additional rub if desired.