Preheat to 375 degrees F.
In a standing mixer fitted with a paddle attachment, cream butter and sugar together.
On low, mix in sifted flour, sifted cornstarch and salt.
Separate dough into two parts. Wrap in plastic and chill for about an hour.
Roll out between two pieces of parchment paper.
Roll to a 1/4 inch thickness.
With a cookie cutter, cut out snowflakes
Place cookies on a baking sheet lined with parchment paper.
Bake for 12 minutes.