Remove the crusts from the slices of bread. Spread about 1 tablespoon of peanut butter on one slice of bread and top it with another slice of bread. Repeat with all bread slices to form 3 "sandwiches."
Slice each bread sandwich into 3 or 4 small strips.
Mash the banana in a bowl until smooth. Add the eggs, milk, cinnamon, and vanilla into the bowl with the mashed banana. Whisk until well combined.
Dip each French toast stick into the batter and shake off any excess batter.
Heat a small amount of butter in a pan on low heat and cook the French toast sticks on all 4 sides. Make sure to turn the sticks on all sides to ensure that there is no raw egg on each piece. Allow them to cool before serving.
