01 -
Set your oven to 350 degrees Fahrenheit.
02 -
Line a 9x13 inch pan with parchment paper. Arrange the graham crackers in a single layer along the bottom, breaking them as needed to ensure the entire bottom is covered.
03 -
In a medium saucepan over medium-high heat, combine the butter and brown sugar. Stir continuously until the butter melts and the mixture begins to boil. Let it boil for 3-4 minutes until it starts to thicken.
04 -
Pour the caramel mixture evenly over the graham crackers. Bake in the preheated oven for 6-8 minutes.
05 -
Remove the pan from the oven. Immediately sprinkle the broken chocolate bar pieces over the hot caramel, followed by the mini marshmallows.
06 -
Turn the oven to broil. Place the pan back in the oven until the marshmallows start to turn golden brown, about 1-2 minutes. Watch closely as this process happens quickly and oven temperatures can vary.
07 -
Allow the bars to cool and harden slightly. Cut into pieces and serve.