Using a stand mixer or a hand mixer in a medium bowl, beat butter, sugar, salt, lemon zest and black pepper just until smooth. Add 1 egg yolk and beat for 1 minute. Mix in the flour by hand with a wooden spoon. (A mixer or beaters tend to overmix the dough.)
Place dough onto a sheet of plastic wrap and form into a 2-inch round log. (Can also be divided into 2 logs if you want to freeze a portion.) Chill dough for at least 3 hours or overnight.
Preheat oven to 350°. Mix 2 tablespoons water with second egg yolk and beat lightly. Use the egg wash to brush the exterior of the chilled log of dough. Lightly roll dough in coarse sugar. (Greenspan recommends sanding sugar, but any good coarse sugar will do.) This will add extra crunch and keep the dough from spreading in the oven.
Cut the logs into ½-inch-thick rounds and place on a parchment-lined baking tray about 2 inches apart. Bake 18–22 minutes; halfway through, rotate baking sheet. Remove from oven. Let rest 5 minutes. Cookies will be crumbly and tender so transfer them carefully to a cooling rack and let them cool completely before serving. Makes 2 dozen cookies.
About this recipe
Co-owner Kate O’Donnell, bywater, Warren