Step 1

Preheat oven to 410° degrees F. Line 1 baking sheet with parchment paper or a silicone liner and set aside.

Step 2

In the bowl of a stand mixer, cream together the butter, brown sugar and granulated sugar together with the paddle attachment on low speed for 30 seconds. Increase speed to medium and beat for another 30 seconds, then increase speed to high power and beat for a final 30 seconds or until creamy and smooth. Add in the eggs, one at a time, followed by the vanilla extract. Add in the cornstarch, baking soda, salt, graham cracker crumbs, cake flour and all-purpose flour and mix on low speed until a soft dough comes together. Lastly, gently stir in the chocolate chips, miniature marshmallows and graham cracker pieces. Cover and refrigerate dough for 30 minutes to chill. This is mandatory.

Step 3

Using a digital cooking scale for accuracy, measure out a 6 ounce portion of cookie dough and form it into a tall, roughly shaped ball - not a compact, tightly rolled one like we're used to. Stagger 4 cookie dough balls 3" apart on the baking sheet - no more than 4 dough balls per baking sheet. We're only baking one sheet at a time, so refrigerate any remaining dough.

Step 4

Bake the cookies in the center rack of the oven for 8-12 minutes or until the cookies appear set and look dry and dull on the outside. You can always bake off one cookie to test to gauge how long your oven will take as everyone's ovens differ in time and temperature. Your cookies should be slightly gooey and underbaked in the center. Remember, do NOT over-bake! The cookies will continue to set up some as they cool. Cool the cookies on the baking sheets to set, at LEAST 30 minutes before serving as cookies are quite delicate while hot.