- 10 tablespoons (1 1/4 sticks) unsalted butter, room temperature
- 1 1/4 cups sugar
- 1 teaspoon pure vanilla extract
- 1 teaspoon freshly grated lemon zest
- 1/2 teaspoon salt
- 6 large egg yolks
- 3 cups all-purpose flour
- Preheat oven to 350 degrees. Line baking sheets with Silpat baking mats or parchment paper. Set aside.
- In the bowl of an electric mixer fitted with the paddle attachment, combine butter and sugar. Beat on medium until light and fluffy, about 2 minutes. Add vanilla, lemon zest, and salt. Beat to combine. Add egg yolks, 1 at a time, beating well after each addition, until fully combined. Reduce speed to low, and add flour, 1 cup at a time, beating until fully combined
- Roll a walnut-size piece of dough into a ball, then roll out into a rope about 3 inches long and 1/4 inch in diameter. Shape into a decorative S. Transfer to prepared baking sheet. Repeat with remaining dough, placing cookies about 1 1/2 inches apart on baking sheet. Bake until firm, 12 to 15 minutes. Transfer to wire racks to cool.
The cookies will keep in an airtight container for up to 2 weeks.