1 1/2 cups caster sugar
500-600g (unpeeled weight) spotty over-ripe bananas
1 tsp vanilla extract (optional)
2 1/2 cups self-raising flour
Preheat oven to 180°C. Line a round 23cm square cake tin with non-stick baking paper.
Cream the butter and sugar until pale and creamy, mash the bananas and beat well in to the mixture. It will look curdled but don't panic. Beat in the eggs one at a time adding 1/2 a cup of the flour so the mixture comes together. Add the last 1 cup of flour (and vanilla if using) then beat for one minute on low speed or until well combined.
Pour the mixture into the prepared cake tin & gently shake to level, don't bang it. Bake in oven at 180°C for 45 minutes or until a skewer inserted into the centre comes out clean. Set aside in the cake tin for 10 minutes to cool slightly before transferring the cake to a wire rack to cool completely.