Spread peanut butter onto each piece of bread. Lay banana pieces on top of half of the slices, and sprinkle chocolate chips on top of the same slices. Lay the slices that only have peanut butter on them on top, with peanut butter facing down.
To a casserole dish, add eggs, cream, vanilla, and cinnamon. Whisk until thoroughly combined. Carefully add a sandwich at a time to the egg mixture and turn to coat.
Heat a skillet with butter. Once the butter has melted, add as many sandwiches as can fit in the skillet. Fry three minutes each side, or until golden brown. While they are cooking on the second side, press down on the sandwich with a spatula to flatten it slightly.
To make the chocolate sauce, add chocolate chips to a bowl. Pour cream into a small saucepan. Heat to just before boiling. Take off the heat and pour over the chocolate chips. Stir until melted.
Cut the French toast sandwiches in half and add to plates. Drizzle chocolate sauce over top. Dust icing sugar on top.