For the banana soufflé, heat the butter, stir in the flour and then slowly add the milk until a creamy mixture is formed.
Bring to the boil, stirring constantly, then remove from the heat. Now stir the sugar and yolks into the mixture. Mash the bananas with a fork, mix and season with the liqueur and lemon juice. Stir the banana mixture into the cream. Beat the egg whites until very stiff and fold in carefully.
Grease and line the ramekins, pour in the mixture and place in the oven. Bake the banana soufflé at 180° for about 25-30 minutes.