In a small bowl, mix starch and 1/4 cup milk until smooth. Pour starch mixture very slowly into heating milk while stirring. Continue heating until mixture thickens (consistency of condensed milk).

Remove from heat. Let stand, covered for about 1/2 hour, place into refrigerator to chill 3 hours. Sprinkle powdered cinnamon over custard. Serve with pirouettes or vanilla wafers.