01 -
Preheat your oven to 350°F (175°C). Grease a 9×9-inch baking pan or line it with parchment paper.
02 -
In a medium bowl, combine the graham cracker crumbs and granulated sugar. Add the melted butter and stir until the mixture is well combined and slightly crumbly.
03 -
Press the graham cracker mixture into the bottom of the prepared baking pan to form a crust. Bake the crust in the preheated oven for 8-10 minutes, or until it's lightly golden. Remove from the oven and set aside.
04 -
While the crust is cooling, place the semi-sweet chocolate chips and milk (or heavy cream) in a microwave-safe bowl. Microwave in 30-second intervals, stirring in between, until the chocolate is fully melted and smooth.
05 -
Pour the melted chocolate over the cooled graham cracker crust and spread it out evenly with a spatula.
06 -
Sprinkle the mini marshmallows evenly over the chocolate layer. Return the pan to the oven and bake for an additional 5-7 minutes, or until the marshmallows are puffed and golden brown.
07 -
Optional: Sprinkle the milk chocolate chips on top while the marshmallows are still hot, and let them melt into the bars.
08 -
Allow the bars to cool in the pan at room temperature for 20-30 minutes, then refrigerate for an additional hour to set.
09 -
Once set, cut into squares and serve!