Death by Chocolate Cookies

Whisk together the flour, cocoa powder, baking soda and salt in a medium-sized bowl. Set aside.

Beat butter, sugars, and vanilla in a large mixer bowl on medium speed until pale and fluffy. Beat in egg and egg yolk until combined. Reduce speed to low and gradually add flour mixture, beating just until incorporated. Fold in chocolate chips. Cover the bowl with plastic wrap and refrigerate the dough for 30 minutes.

Preheat oven to 350 F and line two baking sheets with silicone mats or parchment paper. Form 1 1/4″ balls of dough and place them two inches apart on the prepared baking sheets. Bake, rotating pans halfway through, for 9 minutes or until tops are cracked and almost set. Cool for 2 minutes on baking sheets, then transfer cookies to a wire rack to cool completely. Store in an airtight container at room temperature up to 3 days.