¾ cup (1½ sticks) unsalted butter, at room temperature ¾ cup granulated sugar 2 larges egg yolks ½ teaspoon pure vanilla extract ¼ teaspoon kosher salt 2 cups all-purpose flour 1 cup confectioners' sugar 2 tablespoon fresh lemon juice, plus more if necessary 1 teaspoon grated lemon zest
1. With an electric mixer, beat the butter and granulated sugar until fluffy. Add the egg yolks, vanilla, and salt and beat to combine. Gradually add flour, mixing until just incorporated.
2. Divide dough in half and shape into 1¼-in diameter logs. Wrap in wax paper and refrigerate until firm, about 30 min.
3. Preheat oven to 350 degrees F. Slice logs into 3/8-in pieces and space 1½-in apart on parchment-lined baking sheets. Baked until lightly golden, 16 to 20 min. Let coll on baking sheets for 5 min, then transfer to cooling racks to cool completely.
4. In a small bowl, whisk together the confectioners' sugar, lemon juice and zest until it forms a thick but pourable glaze (add more lemon juice if necessary). Dip the top of each cookie into the glaze and let set, about 15 minutes.