Food & Cooking Recipes Dessert & Treats Recipes Cookie Recipes Thousand-Layer Chocolate Chip Cookies 3.8 (139) 3 Reviews By Martha Stewart Editors Martha Stewart Editors Facebook Instagram Twitter Website An article attributed to "Martha Stewart Editors" indicates when several writers and editors have contributed to an article over the years. These collaborations allow us to provide you with the most accurate, up-to-date, and comprehensive information available.The Martha Stewart team aims to teach and inspire readers daily with tested-until-perfected recipes, creative DIY projects, and elevated home and entertaining ideas. They are experts in their fields who research, create, and test the best ways to help readers design the life they want. The joy is in the doing. Editorial Guidelines Updated on August 4, 2020 Print Share Share Tweet Pin Email Yield: 18 to 20 cookies Satisfy your cookie craving with this decadent twist on the classic dessert from Sarah Copeland's "The Newlywed Cookbook." Ingredients 1 cup (2 sticks) unsalted butter, room temperature ¾ cup packed dark-brown sugar ¾ cup granulated sugar 4 large egg yolks, room temperature 1 teaspoon pure vanilla extract 2 ¼ cups all-purpose flour, plus more for work surface ¾ teaspoon baking soda ¾ teaspoon fine sea salt or table salt 9 ounces bittersweet chocolate 1 large egg, lightly beaten ¼ teaspoon fleur de sel (optional) Directions Preheat oven to 375 degrees. Line two baking sheets with parchment paper; set aside. In the bowl of an electric mixer fitted with the paddle attachment, cream together butter and both sugars on medium-high speed until light and fluffy, about 3 minutes. Beat in egg yolks, two at a time; add vanilla and mix to combine. In a large bowl, whisk together flour, baking soda, and salt. With the mixer on low, add flour mixture; mix until just combined. Scrape down sides of bowl and mix to combine. Divide dough into three equal portions. Wrap each portion with plastic wrap and transfer to refrigerator; let chill for 30 minutes. Meanwhile, using a serrated knife, coarsely chop chocolate into thin shards. Set aside. Unwrap one portion of chilled dough and place on a lightly floured work surface. Sprinkle with half the chocolate and top with a second portion of chilled dough. Sprinkle with remaining chocolate and top with remaining portion of dough. Lightly dust with flour and gently roll out dough to a 9-by-6-inch rectangle, about 1 1/2 inches thick. Using a 2-inch-round cutter, cut out 10 rounds of dough. Gather scraps and lightly pat into another 1 1/2-inch-thick rectangle and cut out remaining cookies. Place on prepared baking sheets about 3 inches apart and brush with beaten egg. Sprinkle with fleur de sel, if desired. Transfer cookies to oven and bake until cookies are set, 12 to 15 minutes, switching baking sheets from top to bottom halfway through baking. Let cookies cool slightly on baking sheets, about 3 minutes, before transferring to a wire rack to cool completely. Cookies can be stored in an airtight container for up to 4 days. Rob Tannenbaum Print