Ingredients
1 1/2 sticks (3/4 cup) salted butter, room temperature
2/3 cup sugar
3 large egg yolks
2 cups unbleached all-purpose flour, plus more for dusting
Preparation
Pulse butter and sugar in a food processor until well combined and smooth. Add 2 egg yolks and pulse to combine. Add flour and pulse until dough comes together. On a lightly floured surface, shape into a disk, wrap in plastic, and refrigerate at least 2 hours or up to overnight.
Preheat oven to 350 degrees with rack in top third. On a lightly floured surface, roll out dough to 1/8 inch thick. Using a 2 1/2-inch fluted round cutter, cut out rounds; transfer to parchment-lined baking sheets, spacing 2 inches apart. Reroll scraps once and cut out more rounds, if desired. Using the tines of a fork, press to create a crosshatch pattern. Refrigerate until firm, about 30 minutes.
In a small bowl, whisk together remaining egg yolk and 1 teaspoon water; use to brush tops and sides of cookies. Bake, rotating sheets halfway through, until golden brown, about 15 minutes. Transfer sheets to wire racks; let cool completely.
