250g caster sugar
2 eggs, lightly beaten
1 tsp good quality vanilla extract
250g plain flour, sifted
2 tsp baking powder
4 ripe bananas, mashed with a fork 175g good quality dark chocolate (70% cocoa solids), broken or chopped into small pieces
Preheat the oven to 180ºC and line a 12-hole muffin tray with the appropriate size cupcakes cases.
In a large mixing bowl, cream the butter and sugar until the mixture is pale and smooth, which should take 3-5 min using an electric mixer.
Add the eggs and vanilla extract and beat again briefly (add the eggs one at time making sure they have incorporated well in between). Add the flour and baking powder and beat again until well combined. Stir in the mashed bananas and chocolate pieces using a wooden spoon (careful not to over-stir).
Carefully spoon the mixture into the cupcake cases, filling them to about 2/3 full. Bake in the oven for about 25 minutes. To check they are cooked, insert a skewer in the centre of one of the cakes - it chould come out clean.
Remove from the oven and leave the cakes in their tins for about 10 minutes before placing on a wire rack to cool. Once they are completely cool, ice the cupcakes with chocolate buttercream. If you wish, pop some chopped walnuts on each one. Alternatively, you could simply serve them with no icing at all for a breakfast treat, warmed in a the oven for a few minutes beforehand.