Preheat oven to 350 degrees F, and prepare a 9x13 baking pan with a light coating of cooking spray, followed by parchment paper
In a large mixing bowl, cream the butter and both sugars using a hand mixer until fluffy, about 4-5 minutes.
Add the egg and vanilla to the same bowl, and mix to combine.
In a separate mixing bowl, whisk together the flour, baking soda, baking powder and salt until well combined.
Add the dry ingredients into the wet ingredients, and mix until just combined (don't overmix!)
Lightly crush the graham cracker sheets (I like to put them in a ziploc bag and use my hands to crush them, or you can use a rolling pin. Don't completely crush them).
Fold in the chocolate chips and graham cracker pieces to the cookie dough until thoroughly incorporated throughout.
Spread the cookie dough in an even layer in your baking pan, making sure to get it into all the corners to make as even of a layer as possible.
Bake at 350 degrees F for 16 -18 minutes, or until golden brown. Let cool completely.