With a double shot of chocolate and hazelnut flavors, kids and adults will rave over these filled cookies. The espresso powder is optional, but it intensifies the chocolate flavor.
28 cookies (serving size: 1 cookie)
1. Preheat oven to 350°.
2. Weigh or lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, sugar, cocoa, and salt; stir with a whisk. Place butter in a large bowl, and beat with a mixer at medium speed until light and fluffy (about 2 minutes). Stir egg yolks with a whisk, adding espresso, if desired. Add the yolk mixture and vanilla to butter; beat well. Add flour mixture to butter mixture; beat at low speed just until combined.
3. Turn dough out onto a sheet of wax paper; knead 6 times or until smooth and shiny. Shape dough into 28 (1-inch) balls. Roll sides of balls in nuts, pressing gently. Arrange balls 1 inch apart on baking sheets lined with parchment paper. Press thumb into center of each cookie, leaving an indentation. Bake, 1 batch at a time, at 350° for 10 minutes. Remove cookies from pans; cool completely on wire racks. Spoon a scant 1/2 teaspoon hazelnut-chocolate spread into center of each cookie.