Preheat your oven to 180°C (350°F).
Mash the banana in a bowl.
Add the flaked almonds and egg whites, then mix gently until well combined.
Spread the mixture thinly onto a baking tray lined with baking paper.
Bake in the oven for 15-20 minutes, or until golden.
Remove from the oven and allow it to cool.
Add a layer of melted dark chocolate on top.
Place in the fridge for about 30 min/1 hour to set.
