Mix flour, starch, baking powder, 240 g icing sugar and vanillin sugar. Mix oil and liqueur. Stir in eggs one after the other. Stir in flour mixture. Smooth the dough in a greased and flour-dusted ring cake tin (approx. 2 l capacity). Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 15 minutes.
Halve the chocolate eggs as desired. Remove the cake from the oven. Place the chocolate eggs in the middle of the cake and press them in slightly. Bake the cake in a hot oven at the same temperature for another 45 minutes.
Take the ring cake out of the oven and let it cool down for about 20 minutes. Then carefully turn the cake over onto a cake rack and let it cool down completely. Dust the ring cake with 1 tbsp. icing sugar shortly before serving.