Cut baguette into 1 inch slices, on an angle to create longer slices of bread. Make cuts in the middle of each slice to split it in half for stuffing, but don't cut all the way through.
Slice banana into thin slices and chop peanuts.
Stuff each slice of bread with some banana slices and about a tablespoon of chopped peanuts. Press each slice.
In a wide bowl, whisk together eggs, milk, vanilla, sugar and warmed peanut butter until it's as smooth as you can get it.
Heat up some vegetable oil in a large cooking pan, over medium heat.
Generously coat each slice of stuffed bread in egg mixture on both sides, lightly pressing on bread with your fingers while coating.
Cook for 4-5 minutes on each side, until eggs are cooked and golden brown.
Meanwhile, combine ingredients for sauce in a small bowl and heat it up in a microwave for 30 seconds, at half power. Start whisking slowly to incorporate the ingredients together and then whisk vigorously for a few seconds until smooth.
Top each slice of French Toast with peanut butter sauce. You can add some chopped banana and peanuts on top.