Preheat oven to 300F, then line three half sheet trays by lightly spraying with nonstick spray and covering with parchment paper.
Combine the corn flour, All-Purpose flour, and salt then set aside.
Cream the softened butter and sugar together, then add the eggs one at a time. Be sure to scrape down the sides of your bowl to ensure it is completely emulsified. Then add the dry ingredients and mix until combined.
Fit a pastry bag with a star tip (I use ATECO size 843). Pipe the cookie dough onto the sheet trays in either straight lines or half-moons. If you choose, lightly sprinkle with sugar. Freeze for five minutes then bake for 10-15 minutes, until golden brown.