This recipe for butter cookies is from The Best Recipe by the editors of Cooks Illustrated. They test each recipe with every conceivable combination of ingredients and proportions. The result? You guessed it! The best recipes. Period.

1/2 lb. (2 sticks) unsalted butter, softened
1 cup superfine sugar
1/2 tsp. salt
1 large egg plus 1 yolk
2 tsp. vanilla extract
2 1/2 cups all-purpose flour, plus extra for work surface
parchment paper

Either by hand or with electric mixer, cream butter, sugar, and salt until light and fluffy, about 3 minutes with mixer set at medium speed. Add yolk, beat well, then add whole egg and vanilla; continue beating until well incorporated. Add flour; beat at low speed until flour is just mixed in. Divide dough in half and wrap in plastic wrap. Refrigerate until firm, at least 1 hour (Can be refrigerated up to 2 days or double wrapped and frozen 1 month)

Adjust oven racks to upper- and lower-middle positions and heat oven to 375°. Remove one disk of dough from refrigerator and cut in half. Return unused portion of dough to refrigerator.

Lightly flour work surface; roll dough to 1/8 inch thick, using thin metal spatula to loosen dough. Sprinkle surface and rolling pin lightly with flour as needed to keep dough from sticking.

Cut or form dough into desired shape. Place dough shapes 1/2 inch apart on parchment-lined cookie sheets. Bake, reversing cookie sheets (from top to bottom and back to front) halfway through baking time, until evenly golden brown, 6 to 8 minutes.

Use thin-bladed spatula to immediately transfer cookies to cooling rack. Cool to room temperature. Repeat rolling, cutting and baking remaining dough. Decorate cooled cookies with royal icing, if desired and transfer to an airtight container.