It reminded me of my Emak's request when I first saw this cake in Ros Onigiri's house. I have just finished baking the cake just now as I am going to visit my Emak tomorrow.
The texture is light and it is very easy & fast to make this. However, my cake turned up a bit dry & bitter. So if I make again next time, I will reduce the bic soda & lower the oven temperature. The cake was cooked at 40 minutes instead of an hour. For recipe, please refer here.
Update: The cake mature after 1-2 days which become more moist & enhanced banana flavour. See photo below: