Chocolate vanilla wafers
- 2 cups all-purpose flour, plus more for work surface
- 1/4 teaspoon salt
- 14 tablespoons unsalted butter, softened
- 1 cup confectioners' sugar
- 1 large egg yolk
- 1/4 teaspoon pure vanilla extract
- 4 tablespoons unsweetened Dutch process cocoa powder
Adapted from bing.com
Sift flour, cocoa and salt into a medium bowl; set aside. Put butter and sugar into the bowl of an electric mixer fitted with the paddle attachment, and mix on medium speed until pale and fluffy, 2 to 3 minutes, scraping down sides of bowl as needed. Reduce speed to low. Mix in egg yolk and vanilla. Gradually add flour mixture; mix until just combined, about 1 minute.
Turn out chocolate dough onto a lightly floured work surface. Roll into a 10-inch log, about 2 inches in diameter. Wrap log in plastic wrap, and freeze until slightly firm, at least 30 minutes.
Preheat oven to 350 degrees. Cut log into 1/4-inch-thick rounds; space 1 inch apart on baking sheets lined with parchment paper. If dough becomes too soft to slice cleanly, return to freezer until firm.
Bake until firm to the touch, 10 to 12 minutes. Transfer to wire racks; let cool. Cookies can be stored in airtight containers at room temperature up to 3 days.