In a bowl, whisk together eggs, milk, vanilla, cinnamon, and salt.
Soak the french bread in the mixture for a few minutes or until the bread is saturated. Melt the butter in a large pan and place two pieces of bread down until slightly browned.
Turn over and then arrange bananas over the top.
Add the other slice of bread and then flip the sandwiches.
Use a heavy pan or a lid to press the sandwiches down to make them more like a panini. Brown each side of the sandwich.
When both sides are golden, remove and add more butter, maple syrup, and powdered sugar.