Butter a 9 x 5 loaf pan and preheat your oven to 325. In a small bowl, whisk together the flour, baking soda, cinnamon and salt and set it aside. Using your electric mixer with the whip attachment, beat together the sugar and eggs on medium speed for about 5 minutes until light and fluffy, and then on low speed, slowly drizzle in the oil.

Next add in the bananas, sour cream and vanilla and continue to mix on low speed until well combined. Using a spatula, fold in the flour mix and the walnuts until just mixed and no flour is visible. Scrape the batter into your prepared loaf pan and smooth the top.

Bake for 1 hour to 1 hour and 15 minutes until the top is golden and the middle springs back to a light touch, then allow the loaf to cool in the pan for about a half hour before turning it out onto a rack to cool completely – though you pretty much need to cut yourself a slice straight away, and slather it in butter.