Spread chocolate chips and mini marshmallows on 4 slices of bread and press remaining slices on top to make sandwiches.
Whisk eggs, milk, vanilla, and cinnamon together in a shallow dish.
Dip each stuffed sandwich into the egg mixture, letting it soak for about 20 seconds per side.
Melt butter in a large skillet or griddle over medium heat.
Cook stuffed sandwiches for 3 to 4 minutes per side until golden brown and the chocolate and marshmallow inside are melted.
Immediately press each cooked French toast into crushed graham crackers to coat the outside.
Serve with powdered sugar and maple syrup.