01 -
Turn the oven to 350°F. Coat a 9x13-inch pan with non-stick spray or line it with parchment paper to make lifting the bars out simple.
02 -
Stir crushed graham crackers and melted butter together in a bowl until they stick together. Press this mix into the pan's bottom evenly.
03 -
Evenly spread the sweetened condensed milk all over the graham cracker crust so it covers it completely.
04 -
Scatter 1 cup of marshmallows, all the chocolate chips, and the graham cracker chunks over the milk layer evenly.
05 -
Bake for 15 minutes until the marshmallows start puffing up and the edges bubble a bit.
06 -
Pull the pan out and sprinkle the second cup of marshmallows over the entire surface, making sure no spots are left uncovered.
07 -
Pop the pan back into the oven and cook for 10 to 15 minutes until you see the top marshmallows turn golden and the edges are set.
08 -
Take the pan out and gently place the chocolate bar pieces across the hot marshmallows. They should start melting from the heat.
09 -
Let them cool for at least 15 minutes on a rack before cutting in. For neat slices, cool completely, though they'll still taste amazing when soft.