Pre-heat oven at 180 degrees celsius.
In a mixing bowl, whisk together brown sugar, melted butter, then add eggs gradually and set aside.
Mix the flour with baking soda, salt and set aside.
Mash the banana in a bowl until almost smooth.
Pour the mashed banana into the sugar mixture, stir, add the peanut butter, banana essence and mix in.
Add the flour bit by bit into the banana mixture and stir in.
Grease a baking pan with cooking spray/butter and pour the mixture into it.
Slice a finger of banana and place on top of the mixture.
Bake at 180 degrees celsius for 45 minutes or until a tester inserted into the centre comes out clean.
Remove from oven and let cool.
Banana bread ready to serve.