Ingredients:

• 4 eggs
• 160g sugar
• 80g flour
• 1 sachet vanilla sugar

Separate the egg whites from the yolks. Using an electric mixer, beat the egg whites, gradually adding the sugar and vanilla, until you achieve the consistency of a meringue. Using a spatula, gently fold in the sifted flour, then the egg yolks.

Preheat the oven to 180°. Pour the batter onto a baking tray lined with lightly oiled parchment paper. Spread it out evenly. Bake at 180° for 10 to 15 minutes. Keep watch and remove from the oven when the sponge is golden. Place a sheet of parchment paper on top, cover with a flat tray and flip the whole thing over. Carefully remove the tray and the parchment paper. Cover with a clean kitchen towel and leave to cool. Then spread strawberry jam or Nutella over the sponge and roll it up tightly. Dust with icing sugar if desired.