- Preheat oven 180°C. Sift cornflour, baking powder, bicarb soda, plain flour and cinnamon into a bowl and stir to combine. Into another bowl add eggs and sugar and whisk until light and fluffy.
- Melt butter in a small saucepan on medium heat. Add oil and melted butter to the egg mixture and stir. Add all the wet ingredients to dry and stir to combine.
- Mash 2 of the bananas leaving one aside. Add mashed banana’s to the mixture and gently fold. Add a pinch of salt and pour evenly into the prepared tin.
- Place the whole banana on the top of mixture and scatter with walnuts. Place in the oven and bake for 35-40 minutes.
- Serve with scattered walnuts.