400–500g/14oz–1lb 2oz ripe bananas (about 5), mashed
250g/9oz gluten-free plain flour
¾ tsp ground allspice
1 tsp bicarbonate of soda
115g/4oz light brown sugar
1½ tsp ground cinnamon
¾ tsp ground ginger
¾ tsp ground nutmeg
115g/4oz butter, softened
2 free-range eggs