In a small bowl, whisk together the flour, baking soda, cornstarch, salt, and cinnamon.

In another bowl, beat together the butter and sugars until smooth. Add in the egg and yolk and beat until smooth. Beat in the vanilla extract then stir in the flour mixture until just combined. Stir in the chocolate chips and chunks, reserving 1/2 cup of the chunks for topping.

Refrigerate the dough for at least 2 hours or overnight. If refrigerating overnight, you'll need to take the bowl out of the fridge about a half hour before you plan to bake these so they're scoopable.

Preheat the oven to 350 degrees. In a bowl, crush the graham crackers into coarse crumbs.

Line two baking sheets with parchment paper. Scoop the dough out into heaping Tablespoons, roll in the graham cracker crumbs, then place them about 1 1/2 inches apart on the baking sheets. Bake for 9-10 minutes or until set on the outside, but still puffed and a bit gooey in the center. Remove from oven and place the reserved chunks on top. Allow the cookies to set up and the chocolate to melt for about 5 minutes then remove to a cooling rack to cool completely. 

To serve, roast the marshmallows over the fire then smoosh them between two chocolate chip cookies. HEAVEN.