Preheat oven to 180°C.
Cream butter and sugar together until the mixture is light and creamy.
Add egg and mashed bananas, beating thoroughly.
Sift flour and salt together and add alternately with milk to creamed mixture.
Add nuts and essence.
Pour into a greased 23 cm loaf tin and bake for 1 hour or until skewer comes out clean when inserted.
Leave in tin for a few minutes before turning out on a wire rack to cool.
Serve with butter.