Soak the raisins in the rum to plumpen them. Melt the butter in a frying pan. Add the brown sugar and heat gently, stirring until the sugar has melted, about 2 minutes. Add the bananas and cook until tender, 3-5 minutes, turning once with a spatula. Sprinkle the bananas with cinnamon.
Pour the rum and raisins over the bananas and flambé them, basting the fruit