Design Eat Repeat

0 Preheat oven to 350℉. Spray a 9×13 pan with nonstick cooking spray.
19 Place [adjustable]17[/adjustable] graham cracker squares in the pan so they cover the bottom. Set aside.
20 Add remaining 8 graham cracker squares to a large ziploc bag. Use a rolling pin or metal pan to crush the crackers until you get graham cracker crumbs. This should equal [adjustable]½[/adjustable] cup. Set aside.
21 In a small microwave-safe bowl, melt the unsalted butter  ([adjustable]½ cup, i.e. 1 stick[/adjustable]) for 20-30 seconds until JUST melted. 
22 Add in granulated sugar ([adjustable]¼ cup) and brown sugar (½ cup) and use a spatula to stir until combined (*do not use a mixer!). Add in egg (1 large) and vanilla extract (1 ½ teaspoons), then mix. Next, add in baking soda (½ teaspoon), baking powder (¼ teaspoon), and salt (¼ teaspoon) and mix again. Add all-purpose flour (1 ¼ cups) and graham cracker crumbs (½ cup[/adjustable]), then mix until all the flour disappears into the dough. Lastly, mix in mini marshmallows ([adjustable]1 cup)[/adjustable] and [adjustable]½ [/adjustable]cup of the semi-sweet chocolate chips.
23 Using a spoon or your clean hands, drop the dough into small chunks in the pan. This will help disperse everything so that you can easily smooth it out. (I highly recommend this method rather than trying to spread out a large chunk.) Once all dough as been added, use a spatula or your hands to press down the dough into a smooth layer (being sure to get all the corners). Be careful not to shift around the graham crackers too much.
24 Once spread evenly, sprinkle the remaining ½ cup semi-sweet chocolate chips on top of the dough and lightly press into dough.
25 Bake at 350℉ for 12-14 minutes or until top is a light golden brown and marshmallows are lightly toasted. Do not overbake or your bars will not be soft and chewy.If desired, press on Hershey bar rectangles immediately after baking.Allow to cool before cutting into 24 pieces. Enjoy!