For the egg liqueur ring cake, grease the ring cake pan and sprinkle with breadcrumbs.
Beat the eggs and vanilla sugar with a hand mixer until creamy. Add the sifted powdered sugar by the tablespoonful. Slowly pour in oil and eggnog and stir through. Combine flour, cornstarch and baking powder and fold in.
Pour the batter into the pan and bake at 150 °C convection oven for about 90 minutes. Then let cool for 15 minutes.
Carefully turn out onto a cake rack and let cool. Melt the couvertures separately in a 50 °C water bath, cool and reheat.
Coat the egg liqueur cake in stripes with the light and dark cooking chocolate. Allow the glaze to cool and set for 2-3 hours.