Grilled Molasses Flank Steak with Watermelon Salsa

Smoky steak with sweet molasses on the sides goes perfectly with fresh watermelon salsa.
Put the first 8 ingredients in a 2-gallon zippered plastic freezer bag; squeeze the bag to mix. Add the steak, seal the bag and refrigerate for 4 to 12 hours. Remove the steak from the marinade, discarding the marinade.Preheat the grill to 400-450 ° (high). Grilled steak, covered, 9 minutes on each side or until desired degree of roasting. Remove from the grill and let stand for 10 minutes. Cut into thin slices diagonally across the fibers. Add salt and pepper to taste. Top with watermelon salsa.