In a medium bowl whisk together flour and salt.
Place butter and Redpath® Icing Sugar in the bowl of a stand mixer, beat until light and fluffy. With the motor running, add the egg yolks one at a time followed by the vanilla.
Slowly add the flour mixture to the butter mixture, beat for about 2 minutes or until it comes together into a dough.
Turn the dough out onto a work surface and divide in two. Place each segment of dough on a piece of plastic wrap, pat into a disk about ½ inch thick. Wrap and chill until firm; about 1 hour.
Preheat oven to 350°F (177°C) and line 2 baking sheets with parchment paper.
Place chilled dough on a lightly floured surface. Roll out dough, one at a time (rotate dough occasionally so it doesn't stick to your workstation), into a ¼ inch thick circle.
Using a 3-inch flower shaped cookie cutter cut dough into 12 flowers, rerolling once if needed. Transfer flowers to prepared baking sheet. Repeat with second dough, and refrigerate for 30 minutes.
Place chilled cookies in preheated oven and bake for 12-14 minutes, rotating pans once, or until the edges are just starting to brown. Remove from oven and let cool for 5 minutes. Transfer cookies to a cooling rack and let cool completely.