Preheat the oven: Set your oven to 350°F (175°C) and grease a 9 x 13-inch baking pan with non-stick butter spray.

Make the crust: In a medium bowl, combine graham cracker crumbs, powdered sugar, and melted butter. Mix until well combined.

Form the crust: Press the graham cracker mixture evenly into the bottom of the prepared pan, compacting it along the edges and up the sides.

Bake the crust: Bake for 5-8 minutes, or until the edges are golden brown. Remove from the oven and let it cool slightly.

Add chocolate: Lay the Hershey’s chocolate bars over the graham cracker crust, covering it evenly. Return to the oven for 3 minutes, or until the chocolate begins to melt.

Add marshmallows: After the chocolate has melted, sprinkle mini marshmallows evenly on top and press them gently together.

Broil the marshmallows: Set the oven to broil and broil the marshmallows for 1-2 minutes, watching closely, until they brown.

Cool and cut: Remove from the oven, let the bars cool completely, and then cut them into squares. Serve and enjoy!