Preheat and Prepare: Preheat your oven to 180°C (160°C fan) and line a 12-hole muffin tin with paper liners.

Combine Dry Ingredients: In a large bowl, whisk together the plain flour, bicarbonate of soda, baking powder, salt, cinnamon, and nutmeg. Whisking helps to aerate the flour and distribute the raising agents evenly.

Mash the Bananas: In a separate medium bowl, mash the ripe bananas thoroughly with a fork until they are mostly liquid with only a few small lumps remaining.

Mix Wet Ingredients: To the mashed bananas, add the light muscovado sugar, room temperature egg, vegetable oil, melted butter, and vanilla extract. Whisk everything together until it's well combined and the sugar has started to dissolve.

Combine Wet and Dry: Pour the wet ingredients into the bowl with the dry ingredients. Using a spatula, gently fold the mixture together until just combined. It's very important not to overmix! Stop as soon as you no longer see streaks of dry flour. The batter will be lumpy, and that's exactly what we want.

Rest the Batter (Optional but Recommended): For the best rise and a lovely domed top, let the batter rest at room temperature for 15 minutes before baking. I find this little pause makes a noticeable difference.

Fill the Muffin Cases: Divide the batter evenly among the 12 muffin liners. An ice cream scoop is a brilliant tool for this, as it ensures each muffin is the same size. Fill each liner about three-quarters full.

Bake to Perfection: Bake in the preheated oven for 20-22 minutes. You can check for doneness by inserting a wooden skewer or toothpick into the centre of a muffin – it should come out clean or with a few moist crumbs attached.

Cool: Let the muffins cool in the tin for 5 minutes before carefully transferring them to a wire rack to cool completely. This prevents them from becoming soggy.