Iced Shortbread Cookies

Beat butter and sugar with an electric mixer on medium speed until well combined, about 1 minute. Add vanilla, and beat just to combine, about 15 seconds. Whisk together flour and salt in a medium bowl. With mixer remaining on low speed, add flour mixture to butter mixture slowly, stopping mixer just before all flour is incorporated. Turn dough out onto a large sheet of parchment paper, and work gently by hand to pull mixture together to form a 1/2-inch-thick disk. Dough will be a little sandy. Fold parchment over disk, wrap in plastic wrap, and chill 1 hour.

Preheat oven to 350ºF. Turn dough out onto a lightly floured surface, and roll dough to about 1/4-inch thickness. Using cookie cutters, cut out cookies, and place on 2 parchment paper-lined baking sheets.

Bake in preheated oven until cookies are just beginning to brown around edges, about 13 minutes, rotating pans top to bottom halfway through baking. Remove pans to wire racks, and cool 5 minutes. Remove cookies with a spatula to wire racks, and let cool completely, about 30 minutes. Spread Snowy White Icing on cooled cookies, and decorate with sprinkles as desired.