Trim the banana stalks and cut lenghways keeping the peel on.

In a saucepan heat the maple syrup and margarine until it starts to simmer. Then brush the cut sides of the banana with a little of the maple syrup mixture.

Heat a griddle pan over a high heat. Place the banana cut side down onto the pan and grill for 2 minutes. Turn over and grill peel side down for a further minute. Remove from the pan and carefully remove the peel.

Spread the peanut butter on 1 slice of bread, top with the banana, remaining syrup, melted dark chocolate and slice of bread. Lightly spread margarine on the top and bottom of the sandwich.

Place the sandwich onto the griddle pan over a medium heat. Grill for 2 minutes on each side until golden brown and toasted to perfection.