Preheat oven and line loaf pan. Whisk dry ingredients together. In a seperate bowl, mash bananas, then mix in the rest of wet ingredients. Add dry to wet and mix gently until just combined. Pour into prepared pan. Bake at 180°C/350°F (160°C fan) 70 minutes.

Preheat oven to 180°C/350°F (160°C fan-forced). Arrange the shelf so the loaf will sit in the middle of the oven.

Prepare the pan - Scrunch a 40 cm / 16" sheet of baking / parchment paper and press it into a loaf pan (21.5 x 11.5 x 7 cm / 4.5 x 8.5 x 2.75"), leaving overhang on the sides for easy lifting.

Whisk dry - Mix dry ingredients in a bowl, whisk together the flour, baking soda, salt, cinnamon and allspice until well combined.

Mash Bananas - In a large mixing bowl, mash the bananas with a potato masher until mostly smooth. Measure out 1 3/4 cups - save the excess for your morning smoothie. (Note 4)

Add wet - Add the brown sugar, eggs, extra yolk, sour cream, melted butter, oil and vanilla. Whisk until combined.

Add dry - Pour the dry ingredients into the wet. Fold gently with a spatula until the flour is just incorporated. Having a few little flour lumps is ok, it's better than overmixing which will make your banana bread firmer rather than soft.

Fill pan - Pour the batter into the prepared pan and smooth the surface.

Bake - Put the banana bread in the oven and bake for 70 minutes, until a skewer inserted in the centre comes out clean (turning the pan around halfway through cooking). While cooking, a crack will naturally appear along the top of your banana bread. The centre continues to expand, it pushes through the firm crust, creating that classic split. (Note 5)

Cool in the pan for 10 minutes, then lift out, and place on a wire rack. Let it cool for an hour before slicing. (Note 6)

Serving - Serve banana bread slices slightly warm or at room temperature. It’s great on its own, or spread with a little butter. Perfect for breakfast, afternoon tea, or a quick snack any time of the day.