Preheat oven to 325 degrees F. Grease a 9×5-inch loaf pan.
Combine bananas, sugar, egg, and melted butter together in a bowl.3 ripe bananas
In a separate bowl, mix flour, crushed graham crackers, baking soda.
Add flour mixture and chocolate chips to banana mixture.½ cup chocolate chips
Stir all together until batter is just mixed.
Pour ⅓ batter into the prepared loaf pan.
Press marshmallows evenly into batter.15 full size marshmallows
Cover with the remainder of the batter.
Bake in preheated oven for approximately one hour, or until a toothpick inserted in the center of the bread (not into a chocolate chip or marshmallow) comes out clean.