Combine rub ingredients and slather onto both sides of the cowboy steaks.
Preheat pellet grill to 225 degrees F.
Place steaks on the cooking grate and cook to an internal temperature of 120 degrees F (about 45 minutes).
Remove steaks from grill, cover and set aside. Turn pellet grill to its maximum temperature.
Place steaks back on the hot grill. After four minutes, rotate 45 degrees to create a diamond pattern of sear marks. After four minutes turn over and repeat on the other side.
Once seared to perfection, remove steaks from grill and place onto a clean cutting board. Let rest for 5-7 minutes and serve with a dollop of flavored butter on top, or carve and share.