In large bowl, comine 1/2 cup sugar and butter, beat until light and fluffy. Add flour and cornstarch, dried butter powder.( this should be available from a cake decorating shop, etc) adds just the best butter flavor -- and mix well.
Divide dough into 18 equal pieces, shape into balls.
Roll balls in 3 tbls sugar.
Place 2" apart on ungreased cookie sheets.
For each cookies, flatten ball of dough firmly with cookie stamp.
Bake at 350* for 9-12 minutes or until bottoms are very light golden brown.