Preheat the oven to 350 degrees F.
Prepare the brownie batter as per the package instructions.
In a bowl, whisk together flour, baking soda, and salt; set aside.
In another bowl, cream together melted butter, brown sugar, and white sugar until well blended. Beat in the vanilla, eggs until light and creamy. Mix in the dry ingredients until just blended, and then stir in the chocolate chips.
In a buttered 13×9 baking dish, spread the prepared brownie mix. Arrange graham crackers over the brownie batter. Add the marshmallows and chocolate chips.
Top it all with the cookie dough, trying to flatten it out to cover the marshmallows. Bake for 30-35 minutes or until a toothpick comes out clean. If the top starts to brown, cover with foil. *Allow it to cool completely before cutting into bars.*