- 1 cup (2 sticks) unsalted butter, room temperature
- 2/3 cup powdered sugar
- 2 large egg yolks
- 4 teaspoons vanilla extract
- 2 cups all purpose flour
- 1/2 teaspoon salt
- 1 1/2 cups finely chopped toasted hazelnuts (about 6 ounces)
- 4 ounces semisweet chocolate, melted
- Preheat oven to 325°F. Line 2 large baking sheets with parchment paper. Beat butter in large bowl until creamy. Gradually add sugar, beating until fluffy. Beat in yolks and vanilla. Beat in flour and salt. Stir in nuts. Transfer dough to work surface. Flatten into disk. Wrap in plastic; freeze until cold, about 10 minutes.
- Roll out dough on floured surface to 1/3-inch thickness. Using 2- to 3-inch star cookie cutter, cut out cookies. Transfer to baking sheets, spacing 1 inch apart. Gather dough scraps; reroll dough and cut out additional cookies. Bake cookies until pale golden (rotate baking sheets after 15 minutes), about 20 minutes. Transfer cookies to rack; cool.
- Spoon chocolate into small plastic bag. Cut off tip from 1 bottom corner of bag to allow small ribbon of chocolate to come out. Drizzle chocolate over cookies. Let cookies stand until chocolate is set. (Can be made ahead. Store in airtight container at room temperature up to 1 week or freeze up to 1 month.)