Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Grease ten jars (290 ml each) and sprinkle with sugar. Beat eggs, icing sugar, 1 pinch of salt and vanilla sugar until creamy with the whisks of the mixer.
Slowly stir in oil and liqueur in a thin stream. Mix flour, starch and baking powder. Stir briefly into the egg-sugar mixture.
Fill each glass about half full with dough. Sprinkle with sugar. Bake in a hot oven for about 35 minutes. Remove and let cool on a cake rack.