Pre-heat the oven to 180C / 350F.

Using an electric mixer cream the butter and sugar.

Add the eggs one at a time ensuring they are fully incorporated after each addition. Scrape the bowl if necessary and beat for about 2 minutes.

Add the banana's and mix briefly to combine.

Sift the flour and baking powder into the bowl and by hand mix this into the batter.

Add the walnuts and stir these through.

Empty the banana bread batter into a loaf tin that has been lined with baking paper (I always like to line the loaf tin with paper as this helps to prevent over browning of the outer part of the loaf which can happen when you are baking a loaf or a bread for a long period of time).

Bake for 70 - 80 minutes (depending how thick your loaf tin is) and until golden brown and springy to the touch. I also always insert a sharp knife into the thickest part of the loaf and ensure that it comes out clean.