Combine the chili powder, garlic powder, onion powder, salt, pepper, and cinnamon in a bowl. Rub the mixture all over the flank steak. Let stand for 10 minutes.
Spray or lightly brush the flank steak with olive oil. Place the flank steak on the grill and grill for 8 minutes per side or until desired degree of doneness. Remove the steak from the grill and transfer to a platter. Tent with foil and let rest for 5-10 minutes. Cut the steak diagonally across the grain into thin slices.
Heat the tortillas in a dry skillet one by one or according to the package directions.
To serve, place several steak slices in the center of each tortilla, top with cheese, lettuce and pico de gallo. Fold in half and serve with lime wedges.