1. Preheat your oven to 350 degrees Fahrenheit.
2. Grease a 9×13 inch baking pan using non-stick butter spray.
3. In a medium-sized bowl, combine graham cracker crumbs, powdered sugar, and butter using a spoon (note the melted butter and the crust).
4. Spread the mixture evenly across the bottom of the baking pan, pressing down firmly with your fingers to pack it along the bottom and sides.

Bake in the oven for approximately 5-8 minutes, or until the edges start to turn a light golden brown. Note: the crust will harden as it cools.

1. Remove the pan from the oven and allow it to cool.
2. Lay the Hershey bars on top of the graham cracker layer, covering it as completely as possible.
3. Return the pan to the oven for about 3 minutes, or until the chocolate begins to melt and becomes shiny.
4. Allow it to cool for 1-2 minutes.
5. Place the mini marshmallows on top of the melted chocolate, packing them closely together.
6. Switch the oven to the “broil” setting, and place the pan back in the oven, keeping a close eye on them! They only need about 2 minutes. Every oven varies, so monitor them closely to prevent burning. Remove them from the oven as soon as they start to brown.
7. Allow the bars to cool completely. After the initial cooling, consider placing them in the refrigerator to set further, making cutting easier.