In a container suitable for bain-marie, mix 2 egg yolks (keep the egg whites apart) with 120 g sugar; Add the sifted flour, 2 whole eggs, cooled melted butter and 4 tablespoons of Lemondor lemon juice. Place the recipient in a hot water bath (bain-marie) and stir over a moderate heat until the mixture is creamy. Leave it to cool.
Meanwhile, beat the 4 egg whites with a pinch of salt, progressively adding 80 g sugar: by the end, it must be whipped to a firm consistency. Blend in the cold cream, stirring delicately with a wooden spoon, with movements from bottom to top. Generously butter a soufflé mould with high and smooth edges. Sprinkle with sugar, fill it by three-quarters with the mixture and bake at 180 °C for 45 minutes. Remove from the oven and serve immediately.