Preheat your oven to 350°F (175°C).
In a mixing bowl, cream together the butter, brown sugar, and granulated sugar until light and fluffy.
Add the eggs and vanilla extract, and mix until well combined.
In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add to the wet ingredients, mixing until just combined.
Fold in the chocolate chips, mini marshmallows, and graham cracker crumbs.
Press the dough into a greased 9-inch cake pan.
Bake for 20-25 minutes, or until the edges are golden brown and a toothpick inserted into the center comes out clean.
Allow to cool before slicing and serving.