Beat in as much of the flour as you can with the mixer. Stir in remaining flour. Place 1 inch apart on the prepared cookie sheet. Bake in a 375 degrees F. oven for 5 to 6 minutes or until edges are lightly browned. Cool on cookie sheet 1 minute.
Transfer cookies to a wire rack and let cool.
If desired, decorate cookies with icing and candies. Beat in egg yolks and vanilla. Beat in as much flour as you can. Stir in any remaining flour with a wooden spoon. If necessary, cover and chill dough about 1 hour or until easy to handle.