Mix the raisins with rum and let stand for about 30 minutes.
Lightly toast the flaked almonds in a dry frying pan without adding fat. Peel bananas and cut in half lengthwise. Immediately brush with lemon juice.
Melt sugar and butter in a wide pan over low heat. Add the bananas and roast briefly, turning once. Add the raisins along with the rum and season the bananas with cinnamon.
Continue to simmer until the sugar has dissolved. Arrange the bananas and sprinkle with almond flakes.
Serve the Foster bananas while still hot.