- Heat the oven to 180 degrees.
- Put all ingredients together in a bowl and mix until smooth. It is best to crush the banana in advance with a fork. Cut 1 banana in half lengthwise. Keep 1 half separate.
- Place a sheet of baking paper in a cake tin. Carefully pour the mixture into the cake tin.
- Place the other half of the banana on top of the cake mixture. Put in the oven and bake for about 50 minutes at 180°C.
- Prick the centre of the cake with a knife to see if it is cooked. Remove from the oven and allow to cool.
Tip: serve with some extra yogurt, cheese, quark, etc.