Peel the bananas and cut in half lengthways. Place cut side down in a well-buttered fireproof baking dish and sprinkle with the lemon juice. Blend the sugar and spices and sprinkle over the bananas.
Dot with the butter and place under a hot grill for about 5 minutes, or Until the bananas are golden and soft and the sugar has melted. Baste the bananas occasionally with the juices in the dish.
Warm the rum in a saucepan with a little lemon rind. Flame and pour over the bananas. The flame will burn for about 1 minute. Serve at once with double cream.