Preheat your oven to 350°F (175°C). Grease and line an 8x8-inch baking pan with parchment paper.
In a bowl, combine graham cracker crumbs with melted butter. Press the mixture firmly into the bottom of the prepared pan to form the crust.
Sprinkle chocolate chips evenly over the crust.
Top with mini marshmallows, covering the entire surface.
Bake for 12–15 minutes, or until the marshmallows are golden brown and gooey.
Remove from the oven and let cool completely before slicing into bars.
For added flair, drizzle with melted chocolate or caramel before serving.