I made one 8inch round cake and 7cupcakes with the following recipe. I found it a bit too sweet for me, but I guess depends on the ripeness of the bananas, you have to adjust the amount of sugar, either increasing or decreasing. Also, these cakes don't grow at all, so you can fill the tin way up to the top, but just beware that the cooking time may take longer, about 5more mins or so. By the way, I added some chopped walnuts and chocolate chips into the batter, just my personal preference, is optional and it still tastes good without the additional ingredients.
Banana cupcakes Recipe:
3eggs
100g sugar
1heaping tablespoon honey
100g oil or melted butter
235g mashed ripe bananas,about 2 small
200g all purpose flour
1/2tsp baking powder
1/2tsp baking soda
1) in high speed, beat eggs and sugar until pale in color and reach a thick ribbon like consistence, set aside.
2) mix together remaining ingredients in a separate bowl, pour into the egg mixture and combine well.
3) bake in 350F preheated oven for 15mins or golden brown and cooked through.