Beat egg whites alone until firm at the beginning, then continue beating with 25 g confectioner’s sugar. Beat the egg yolks with 75 g powdered sugar until creamy.
Fold the flour and 1/4 of the beaten egg whites into the egg mixture, then carefully fold in the remaining beaten egg whites.
Cover the baking tray with parchment paper and spread the dough to a rectangular shape about 1/2 cm thick. Place the baking tray in the preheated oven and bake at about 200 °C for about 10 minutes until light brown.
Turn the sponge out onto a baking tray sprinkled with powdered sugar, carefully peel off the parchment paper, spread jam on the spot and roll up quickly. Sprinkle with powdered sugar.
Preparation Tip:
The edges should not harden, in case this does happen, briefly place a damp dishcloth on the sponge.