01 -
Preheat oven to 350 degrees Fahrenheit.
02 -
In a 9x13 pan lined with parchment, place the graham crackers in a single layer along the bottom, ensuring the pan is fully lined by breaking crackers if necessary.
03 -
Add the butter and brown sugar in a medium saucepan over medium-high heat. Stir constantly until the butter has melted. Let the mixture boil for 3-4 minutes until it starts to thicken.
04 -
Pour caramel mixture evenly over the graham crackers and bake for 6-8 minutes.
05 -
Remove the pan from the oven, sprinkle with the broken chocolate bar pieces, and then the mini marshmallows.
06 -
Turn the oven to broil then place the pan back into the oven until the marshmallows start to get golden, about 1-2 minutes. Watch it closely, as this happens very quickly because every oven is different.
07 -
Allow the bars to cool and slightly harden then cut into pieces and serve.