In a medium bowl stir flour, cornstarch and confectioners' sugar.
In a large
bowl with mixer at medium speed beat margarine until smooth. Add flour mixture and
vanilla extract and beat until combined. (Dough will be past the crumbly stage.
It will be a heavy batter).
Refrigerate for 1 hour.
Shape into 1-inch balls. Place about 1 1/2 inches apart on an ungreased cookie
sheet; flatten with a lightly floured fork.
Bake at 375 degrees F for 10 to 12 minutes
or until edges are lightly browned.
Paste food color may be added to dough before forming balls.