Preheat the oven to 350°F (175°C) and prepare a baking dish.
In large mixing bowl, combine graham cracker crumbs, melted butter, sugar, and salt.
Press the mixture evenly into the bottom of the baking dish.
Bake the crust for 10 minutes until lightly golden.
Remove from the oven and sprinkle chocolate chips over the hot crust.
Evenly distribute mini marshmallows over the melted chocolate.
Return the dish to the oven and bake for an additional 5-7 minutes.
Let cool completely before cutting into squares.