Break the sponge cakes into medium size pieces and spread each piece with jam. Place in a large glass bowl and sprinkle over the raspberries. Add the sherry until the cakes are saturated. Make the custard: Heat half the cream in a small saucepan. Blend the egg yolks, sugar and cornflour together in a basin and when the cream is hot pour over the mixture , stirring constantly. Return to the pan and reheat gently until thick, then allow to cool. Slice the bananas, mix in with the raspberries, and pour the custard over. Whip up the remaining cream and spread over the custard. Decorate with the flaked almonds. Cover and chill for 3 - 4 hours before serving. This is nice served with a good dessert wine, one of the Australian or Californian Muscats would be great.