-sifted Preheat oven to 230ºC . Place 4 shallow 23 cm oval gratin dishes on a baking sheet. In each, put 1 teaspoon of jelly, 1 tablespoon of cream and 1 piece of butter. In a mixer, beat the egg whites on medium-high speed until they form soft peaks. Gradually add vanilla sugar and lemon juice and continue to beat until stiff and shiny. Use a large rubber spatula to gently fold egg yolks and flour into the beaten whites. Use a spatula to transfer 3 large mounds of the mixture to each of the baking dishes; shape and smooth them. Bake until puffed and golden (about 8 minutes.) Serve immediately.