For the sponge cake roll, beat sugar, vanilla sugar and eggs until thick and fluffy. Stir in flour very briefly and pour into a baking tray lined with baking paper.
Bake at 170° C for 20 minutes. Turn out onto a tea towel sprinkled with powdered sugar and remove the baking paper. Stir the apricot jam until smooth and spread evenly over the sponge. Immediately afterwards, form a roll with the help of the tea towel, let it cool and sprinkle the sponge cake roulade with powdered sugar.