Preheat the oven to 400 F/200 C/190 C fan/ gas mark 6. Lightly grease or line your muffin pan with 12 paper cases. Whisk together both flours and baking powder.
In another bowlwhisk together the eggs, oil, milk, peanut butter, maple syrup and vanilla extract until thoroughly combined.
Partly mash the banana (it should be quite lumpy) and stir into the wet mixture.
Graduallystir in the dry ingredients until they are no longer visible. The mixture should be lumpy.
Spoon the batter into your muffin cases and bake in the centre of the oven for 26 minutes until the tops are lightly browned (and the skewer inserted into the middle comes out clean).
Remove from the oven and set aside for 5 minutes then transfer your peanut butter and banana muffins to a rack to cool completely.
Notes
Use ripe bananas for maximum flavour and natural sweetness.
I recommend partly mashing the banana with a fork (rather than pureeing it) for added texture and a more intense banana flavour.
Weigh the banana without the peel.
I recommend using natural (runny) peanut butter without any additives.
Do not overstir the batter (it should be lumpy). Stir just to combine.
Best served within 2 days. Once cooled completely store in an airtight container.
These whole wheat banana peanut butter muffins are delicious a little warm (you can microwave them for a few seconds before serving).