Peel and mash the bananas, add to a mixing bowl.

Add the sugar, oil, and vanilla essence. Mix well.

Sieve the whole wheat flour, baking soda, baking powder, and salt.

Add this to the mixing bowl, mix well till the batter is smooth.

Add the walnuts, fold in. Pour batter into a greased baking tray.

Bake in a preheated oven at 180 Degrees Celsius for 45 minutes or until done.