125g butter (if unsalted add 1/2 teaspoon salt to flour)
330g sugar
280g mashed banana (avocado masher works well, or a fork and a cup/bowl)
1/2 teaspoon vanilla extract
2 eggs
100ml buttermilk
225g self-raising flour
1/2 teaspoon bicarb soda
Method
Preheat oven to 180°C.
Cream butter and sugar.
Add banana, vanilla and eggs. Mix. Suggest not using a whisk (I had to try out my fancy new whisk from Amazon last time I made this, and the banana tends to get stuck).
Mix in the buttermilk.
Sift the flour and bicarb soda together (and salt if using unsalted butter). Add to wet ingredients and mix.
Dump mix in a loaf pan, cook for around 50 minutes.