Combine marinade ingredients in a mixing bowl and mix until thoroughly combined.
Add flank steaks to the mixing bowl and cover them entirely in the marinade, or place the marinade and steaks in a Ziplock bag and seal. Refrigerate for 8-12 hours.
Preheat your pellet smoker to 225ºF with Oak or Hickory.
Remove steaks from the marinade, pat dry with a paper towel, and apply dry rub.
Smoke the steaks in the preheated smoker for about 1 hour, or until the desired doneness is achieved.
Use a meat thermometer to check the internal temperature of the steaks and follow the temperature guidelines provided for desired doneness.
Remove the steaks from heat, allow them to rest in foil for 5-10 minutes, and then cut against the grain in thin slices.
Serve with your choice of side dishes.