Preheat the oven to 175C/350F
Place 8 cupcake liners into a muffin tray and grease.
Place the egg whites in the bowl of a kitchen stand with a whisk attachment.
Whisk the egg whites on medium until soft peaks form.
Add the maple syrup slowly whilst still whisking.
Add the mashed banana and vanilla extract.
Continue to whisk.
Add the egg yolks and whisk until combined.
In a separate bowl sift the coconut flour and baking powder.
Add the dry ingredients to the wet and whisk on low til combined.
Add the milk and whisk on high until combined.
Spoon cupcake mixture into the liners, smoothing the top of each cake.
Bake in oven for 23-25 minutes, or until cooked through.
Remove from oven. Allow to cool in the tray for 10 minutes before removing from the tray.
Cool completely before frosting.