1. Whisk together the bourbon, brown sugar, salt, and pepper in a bowl, and pour over steaks in a glass dish. Let sit for 10 minutes.
2. Preheat grill to medium-high.
3. Place steaks on preheated grill and cook for approximately 13 minutes total time for rare, 17 for medium, or 20 for well done, TURNING ONCE during cooking time.
4. Remove to a plate and let rest for 3 minutes before cutting. Serves 2.