Chunky Twix Cookies

Preheat oven to 325°F. Line 2 baking sheets with parchment paper; set aside. In a medium bowl, whisk together flour, baking soda and salt; set aside. In the bowl of a stand mixer fitted with the paddle attachment, beat butter and sugars until thoroughly combined. Beat in egg, yolk and vanilla until combined. Add dry ingredients and beat at low speed just until combined. Stir in chopped Twix and chocolate chips. Roll a scant 1/4 cup dough into ball. Holding dough ball in fingertips of both hands, pull into 2 equal halves. Rotate halves 90 degrees and, with jagged surfaces facing up, join halves back together into one ball so that the top surface is jagged. Place onto prepared cookie sheet, spacing 2 1/2 inches apart. (Dough can be refrigerated up to 2 days or frozen up to 1 month—shaped or not.) Bake until cookies are light golden brown and outer edges start to harden yet centers are still soft and puffy, 15 to 18 minutes (start checking at 13 minutes). (Frozen dough requires an extra 1 to 2 minutes baking time.) Cool cookies on cookie sheets. Remove cookies using a wide metal spatula. Serve or store in airtight container.