Preheat the oven to 350° F. Line baking sheets with parchment paper.
In the bowl of a stand mixer add the butter, brown sugar, & granulated sugar. Mix together until very light and creamy, 2-3 minutes.
Add the eggs and vanilla and mix until evenly combined.
Add the flour, soda, & salt. Stir. Next add graham crackers, whole, (don't worry, they break up to the perfect size) chocolate chips, and marshmallow bits and mix until incorporated.
Scoop the dough onto the prepared baking sheets
Bake for 10 minutes until just golden on the edges and a little crackly on top. Let the cookies sit for a few minutes on the baking sheet before removing to a wire rack to cool completely.
