Make ahead (the night before): For Dulce de Leche, remove the label from can of sweetened condensed milk. Submerge in large pot filled with water and let boil for 3 hours. Let cool and set aside.
Crush graham crackers or blend in a Magic Bullet until fine. Add butter and press into a greased, medium-sized rectangular oven safe pan.
Microwave all ingredients for chocolate filling and pour over top of graham cracker crust.
Add marshmallows to cover entire pan.
Cook in 425 degree oven for 16 minutes. Remove from oven and immediately sprinkle with chocolate chips.
Once cooled for about 5 min, add Dulce de Leche to a plastic sandwich bag and cut a small hole in the corner, then drizzle overtop of chocolate chips and marshmallows.
