1. Preheat the oven to 180C/350F<div>2. Sift flour, bicarbonate of soda and salt into a large bowl.</div><div>3. In a separate bowl cream the butter and sugar together until light and fluffy.</div><div>4. Add the eggs, mashed bananas, buttermilk and vanilla extract to the butter and sugar mixture and mix well. &nbsp;Fold in the flour.</div><div>5. Grease a 20 cm x 12.5 cm (8 in x 5 in) loaf tin and pour cake mixture into the tin.</div><div>6. Transfer to the oven and bake for about one hour, or until well risen and golden-brown.</div><div>7. Remove from the oven and cool in the tin for a few minutes. &nbsp;Then turn onto a wire rack and allow to cool completely.</div>