You could try this one:
CHOCOLATE BANANA MUFFINS
5 oz Doves Farm flour
2 tsps of gf baking powder
Half teaspoon Xanthan gum
2 oz butter
1 oz cocoa
Half bar good quality plain chocolate, chopped into small pieces
1.75-2 oz light muscovado sugar (according to taste)
2 ripe bananas, mashed
1 large eggs, beaten with?
1 tsp good vanilla essence
Milk to bind
2 tbsp quinoa flakes
Sieve the flour and baking powder together into a large mixing bowl and rub in the butter to breadcrumb stage. Add quinoa flakes.
Sieve in the cocoa and add chopped chocolate, bananas and sugar. Mix these together evenly then add the eggs and vanilla essence.
Add enough milk while you beat the mixture until the consistency is slightly stiffer than that for a sponge cake.
Spoon into cake cases in a deep muffin tin, piled up quite high (they don?t rise as much as sponge buns so you?ll have to start big). You should get about 14 muffins from this quantity.
Bake in the middle of a pre-heated oven, Gas 6, 200ºC, 400ºF for about twenty minutes. They will be ready when they feel quite firm on top, not as springy as sponge buns so once you get to that stage leave a minute or so longer. Remove from the oven immediately ? you might need to lever them out of the tins with a palette knife as they are quite soft when warm ? and leave to cool on a wire tray.
These will keep for up to a week in a sealed box at room temperature.