Peel the 4 bananas. Use a paring knife to slice them up into 1-inch thick slices. Hold these aside.
In a large bowl, beat together the ¼ cup smooth peanut butter, 2 large eggs, 1 cup milk, room temperature, ¼ cup granulated sugar, 1 teaspoon ground cinnamon, ½ teaspoon pure vanilla extract, and ¼ teaspoon salt until everything is well-mixed.
Heat up a large skillet over medium heat. Have the 6 tablespoons butter, 8 slices good, fresh-baked white or wheat bread, and egg mixture on hand along with a spatula and a plate(s) to hold the cooked toast.
When the skillet is hot, add in a small pat of butter and move the pan to coat the surface as the butter melts. Dip a slice of bread into the egg mixture and coat both sides thoroughly. Place it into the skillet.
Cook it for about 1 minute until the side is lightly browned; flip it over and cook the other side for another minute or so until it is browned, too. Transfer the cooked slice to a plate. (You can also put the slices on a sheet pan in the oven set to 200°F to keep them warm.)
Add another small slice of butter to the pan, and continue with these steps until all of the bread slices are dipped and cooked.
Divide the cooked slices of French toast between the breakfast plates. Top each plate with sliced bananas. Serve the toast with extra butter if desired.
Give the peanut butter-maple syrup a quick stir and pass it around to pour over the French toast. Enjoy immediately!