For sauce, place frozen strawberries with syrup in a medium skillet and heat over medium-low heat until warm. Set aside. For filling, combine ricotta cheese, vanilla, sugar, and cinnamon in a small bowl. Place a quarter of the filling in each tortilla. Fold opposite sides in and roll up the bottoms, tucking in the ends. Heat the butter in a large non-stick skillet over medium heat. Add the tortilla rolls and cook for 4-5 minutes or until well browned and crisp, turning once halfway through. Top each roll with some sauce. Sprinkle with powdered sugar if desired. Serve immediately. Serves 4.