Mash the banana with a fork. Preheat the oven to 180°C.
Add the A ingredients to a bowl in order from the top. Use a whisk to combine.
Add the B ingredients into the bowl. Mix together well and then pour in the cake pan. Bake for 30-40 minutes.
Story Behind this Recipe
Since the cake I had made using leftover banana came out really tasty, I made a rice flour version.
Since this is rice flour, make sure to mix everything together very well. Adjust the baking time as necessary. When an inserted skewer comes out clean, it's done. It will become even more moist if you cover it with plastic wrap after it has cooled.