Heat oven to 350 degrees. Lightly greas jelly roll pan ( 15.5x 10.5x1). Mix sugar, margarine and egg yolk in large bowl. Stir in flour and cinnamon. Press in pan. Beat egg white and water until foamy; brush over dough. Sprinkle with walnuts. Bake 20 to 25 minutes or until very light brown. Immediately cut into about 3x1 inch strips. Cool on wire rack. Makes 3.5 dozen cookies. Gold Medal cookies and bars cookbook