Preheat oven to 175 degrees Celsius

Mash the bananas

In a large bowl, whisk together the butter and sugar. Add the eggs and vanilla and lemon juice, mix well. Combine the flour, baking soda, baking powder and salt, stir into the butter mixture until smooth. [must be sifted]

Finally, fold in the sour cream, walnuts and bananas. Spread evenly into the prepared pan.

Bake for 1 hour. Cool loaf in the pan for 10minutes before removing to a wire rack to completely cool