For the Kitkat Smarties cake, beat eggs, sugar, vanilla sugar until creamy. Mix cornstarch, flour, baking powder and stir in. Pour the batter into a springform pan and bake at 200 °C for approx. 30 min. and let cool.
For the cream, bring the whipped cream to the boil, pour over the chocolate and stir until everything has melted. Beat the butter with the powdered sugar and vanilla sugar until fluffy and mix everything together.
Then season to taste and mix in cocoa to taste. Then put the cream in the refrigerator. Cut the base in two.
Spread some cream on the bottom cake layer, put the second cake layer on top. Spread some cream on top again and place the last cake layer on top. Spread the rest of the cream all over the cake.
Then place the kitkats one by one on the edge. To secure them, I would still wrap a ribbon around the cake. Finally, simply sprinkle the Smarties over it and let it cool in the refrigerator for about 3 hours.