In a bowl, add the egg and beat well with a whisk.
Add the tapioca starch, the ripe banana, the cornmeal and the baking powder, mix all the ingredients together very well until incorporated.
Add the water and mix again.
Once you’ve done that, grease a small skillet (14cm diameter) with unsalted margarine.
Pour in all the cake batter and spread.
Next, turn on the heat at low power and let it cook for 10 minutes.
After this indicated time, flip the skillet and let it cook on the other side for another 5 minutes.
Serve.