1Preheat oven to 160 degrees Celsius.
2Separate the egg whites and egg yolks in two different bowls.
3Beat the egg whites with 50 grams of powdered sugar until mixture whitens.
4In another bowl, add butter, 50 grams of powdered sugar, and vanilla sugar. Stir until the mixture forms a cream. Add egg yolks, mix until frothy. Stir in egg whites, lifting the dough with a spatula. Add flour, hazelnut powder, ground poppy seeds, and lemon zest. Stir gently to get a nice homogeneous paste.
5Pour into cake rings and bake for 30 minutes. Use two 20 centimeter diameter cake rings.
6The layer of cake with poppy should not be too thick. The size should not exceed 2.5 cm to 3 cm.
7If the cake is too high, then cut size.
8Cool for 10 minutes in pan, then turn out onto wire rack to cool.
9Put the gelatin in a bowl of cold water to soften.
10Beat the quark cheese, icing sugar, and lemon zest.
11Whip 350 grams of cream to obtain whipped cream.
12Squeeze the gelatin.
13Use a double boiler, or a water bath, to heat lemon juice and the 2 remaining tablespoons of cream.
14When the mixture is really hot, add the gelatin sheets one by one. Mix well with a fork to dissolve completely.
15Quickly mix in the quark cheese.
16Gently add the whipped cream, lifting with a spatula .
17Cut the cooled poppy cake the size of plating or cake rings. Place in cake rings, preferably lined with rhodoid film for a clean edge.
18Spread a 2.5 cm to 3 cm layer of mousse evenly on top of poppy cake.
19Soften the gelatin in a bowl of cold water.
20In a saucepan, heat half of the raspberry puree.
21Remove from heat, add gelatin, and stir well to make sure the gelatin melts completely.
22Add the remaining raspberry puree, let cool (Otherwise, the icing will melt the mousse).
23Pour frosting on cake, if needed, level the surface with a spatula. Refrigerate for a least 4 hours, or preferably overnight.
24To unmold, simply remove the ring, then the rhodoïd film, for a very clean cake edge.