HOW TO MAKE IT :
- Mix brown sugar, granulated sugar, butter, egg, egg yolk and vanilla in a large bowl until well mixed. Stir in flour, cocoa powder, baking powder, salt and baking soda until blended (dough will be soft and creamy).
- Divide dough into three equal portions. Wrap each portion with plastic wrap and transfer to refrigerator; let chill for 30 minutes.
- Unwrap the chilled dough and place on a lightly floured work surface. (I dusted my surface with cocoa powder) Roll out to about 1/2-1 inch thick.
- Sprinkle with half the chocolate morsels on top of the first portion of chilled dough. Roll out the second dough ball and then set on top.
- Sprinkle with remaining chocolate and top and then set the final portion of dough on top of that.
- Gently flatten with rolling pin and try to create a square with the cookie dough. You can fold the dough over itself and roll the cookies again if desired. These cookies do not rise very much so the make sure your dough is the desired thickness of the final cookie before moving on to the next step.
- Cut dough into 2-inch squares with a sharp knife and set on a cookie sheet lined with parchment paper about an inch apart. (Cookies do not spread a great deal)
- Re-roll any leftover batter. You can stack it on itself to keep creating layers of chocolate chip cookie dough.
- Bake at 350°F for 11-14 minutes. (The center should not appear wet)
- Cool a couple minutes on baking sheets and then transfer to a wire rack to cool completely.
