First, for the cream, beat 500 g of mascarpone with 1 teaspoon of lemon zest, 2 tablespoons of lemon juice, 100 g of icing sugar and 2 packets of cream stiffener until creamy. Then carefully fold in 1 cup of whipped cream. Now refrigerate the cream until ready to fill.

For the lemon dough, beat 3 eggs with the zest of a lemon, 150 g sugar, 1 tablespoon vanilla sugar and a pinch of salt until creamy. Then stir in 75 ml mineral water and 2 tablespoons lemon juice.

Mix together 75 g flour, 75 g corn starch and 2 teaspoons of baking powder. Fold the flour mixture into the dough alternately with 60 g cooled, melted butter.

Halve the dough, spread it into the cake frame and bake in a preheated oven at 180 C for about 7 minutes until light brown. Do the same with the second half of the dough.

After baking, remove the sponge cake from the baking paper and fill it with the lemon mascarpone cream. Cut the second sponge cake into slices and cover the cream with them. Finally, sprinkle with icing sugar and serve well chilled.