- 2/3 cup roasted and salted hazelnuts
- 2 1/2 cups all-purpose flour
- 1/2 teaspoon baking soda
- 1/2 teaspoon salt
- 2 sticks (1/2 pound) unsalted butter, softened
- 1 1/4 cups sugar
- 1 large egg yolk
- 1 teaspoon pure vanilla extract
- Nutella or another chocolate spread
- In a food processor, finely grind hazelnuts. In a medium bowl, whisk the flour with the ground nuts, baking soda and salt. In a standing electric mixer fitted with a paddle, or using a hand mixer in a large bowl, beat the butter with the sugar at medium speed until light and fluffy, about 3 minutes. Beat in the egg yolk and vanilla, scraping the side and bottom of the bowl. Beat in the dry ingredients at medium-low speed. Divide the dough in half. Pat each half into a round, wrap them in plastic and refrigerate for 15 minutes.
- Preheat the oven to 350°. Position the racks in the upper and lower thirds of the oven. On a lightly floured surface, roll out each piece of dough 1/8-inch thick. Using a 2-inch biscuit cutter, stamp out rounds as close together as possible. Arrange the rounds on large baking sheets, about 1 inch apart. Gather the scraps and reroll, cutting out more cookies.
- Bake the cookies in batches for about 20 minutes, until golden; shift the pans from top to bottom and front to back halfway through baking. Let the cookies cool on the sheets for 5 minutes, then transfer to racks to cool completely.
- Sandwich the cooled cookies with Nutella or another chocolate spread.
The cookie dough can be wrapped in plastic and aluminum foil and refrigerated for up to 1 week or frozen for up to 1 month. Thaw in the refrigerator before using. The baked cookies can be stored in an airtight container for up to 1 week or wrapped in plastic and foil and frozen for up to 1 month.