Grind the bananas well with a fork until they become a puree, add the egg and salt and mix well. Add sifted flour with baking powder and mix well, get a homogeneous and sticky dough.
Put a lot of oil in a saucepan and heat it over medium to low heat. When the oil is dark, soak a tablespoon in the dark oil, take the donut composition and put in the pan, each donut is fried over low heat until browned on all sides.
It can be served with powdered sugar, jam or chocolate.