The bananas should be ripe but not overly ripe. I normally use plain flour (Maida) for making the batter. Amma used atta and I didn't find any taste difference. If you prefer the yellow coloured pazham pori, add 1/2 tsp turmeric powder to the batter. If there is excess batter you can make bread fritters also. Just cut the bread into small pieces and follow the same procedure.