3/4 cup (1 1/2 sticks) unsalted butter, at room temperature 3/4 cup granulated sugar 2 larges egg yolks 1/2 tsp pure vanilla extract 1/4 tsp kosher salt 2 cups all-purpose flour 1 cup confectioners' sugar 2 tbsp fresh lemon juice, plus more if necessary 1 tsp 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 1 1/4-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 1 1/2-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.