Preheat oven to 350oF (180oC).
In a bowl, add bananas. Mash bananas.
To the same bowl, add sugar, Mix until well combined.Then, add water. Mix until sugar has dissolved. Add oil. Mix well.
To the same bowl, sift flour, baking powder, baking soda, salt and cinnamon powder.Mix until dry flour is no longer visible. Do not over mix. Scoop batter into cupcake pan lined with cupcake liners. Fill until about 2/3 full.
Bake in preheated oven, 350oF (180oC), middle position in oven, for 20 minutes or until toothpick comes out clean.
Let cupcakes cool down in pan for about 10 minutes. Then, transfer to wire rack to cool completely.