Peel the bananas and weigh out 200g of banana flesh.
Blend the bananas with the whole egg, egg whites and milk until you have a smooth puree.
Preheat the oven to 180'C.
Zest the orange and grate the chocolate.
Mix together the flour, sugar, bicarbonate of soda, orange zest and grated chocolate. Fold in the banana puree making sure to not over work the mixture.
Spoon the mixture into muffin cases (only fill to 2/3) and bake for 25 minutes.
The muffins should be golden brown and well risen. Check they are cooked by inserting a skewer into the centre. If it comes out clean the muffins are ready. Allow to cool slightly and serve.
«For light and airy muffins make sure you do not overwork the mixture once the banana puree is added. An overworked mixture will make the muffins dense and heavy.»