Sift the flour, salt and cornstarch into a large bowl. Repeat process for the confectioners sugar into a separate bowl. Set aside.
In a large bowl, cream the butter using a hand mixer for about 2 minutes. Once the butter is soft and fluffy, add the confectioners sugar.
Mix on speed #2 to integrate. Scrape down sides of the bowl with a spatula. Add the vanilla and egg. Beat for about a minute until everything is integrated and fluffy.
Add half of the flour mixture and integrate with the spatula. – Transfer the dough to a decorating bag fitted with a large open star tip.
Bake, one pan at a time, until light golden brown at the bottom, 12 to 15 minutes. Allow to cool completely before storing or serving.