Old chocolate cake

For the dough:
4 pc eggs
1 cup (200 ml) powdered sugar
1 cup of flour
3 tbsp cocoa powder
1 packet of baking powder
1 packet of vanilla sugar

For the cream:

1 liter of milk
4 tbsp flour
4 tbsp potato or corn starch
1.5 cups of powdered sugar
2 pc eggs
100 g butter
1 packet of vanilla sugar
400 ml whipped cream