Add the milk, flour, eggs, bananas, salt, baking powder and brown sugar into a blender and blend until smooth. Add a little extra milk or flour to make the batter a pourable but somewhat thick texture. Too thin of pancake batter and your pancakes will be flat. Too thick and your pancakes won't cook evenly. You want them the perfect consistency so you can pour them evenly onto a hot griddle. This texture will vary depending on how large your eggs are as well as your bananas.
Heat a flat griddle to medium heat. Spray with cooking spray. Pour some of the batter onto the hot griddle. Sprinkle with chocolate chips, some marshmallows and some of the crumbled graham crackers. Cook until golden brown on the bottom side and then flip to the other side and cook for a few more minutes. Remove from heat and serve with pancake syrup, butter syrup or just whipped cream. Garnish with extra toppings if you'd like.