According to my calculations these muffins come out at around 91 calories each. Not bad...

I'm not the best at adding up, but they are thereabouts at least
1 banana
20ml sunflower oil
1 egg
100g self raising flour
75g granulated sugar
A grating of nutmeg
Mash the banana well. Beat the egg then mix with the oil and banana. Fold in the flour, sugar and nutmeg. Spoon into 12 muffin cases. Bake for 25 minutes at Gas Mark 4/180C. Cool on a wire rack. Don't rise as much as bought muffins but rather tasty...