Bring 400 ml of the milk to a boil with the sugar and vanilla sugar.

In a separate bowl, mix the egg with the remaining 100 ml milk and pudding powder until smooth.

When the milk is almost boiling add a dash of warm milk to the egg mixture while stirring.

Slowly pour the egg mixture into the boiling milk, stirring well with a whisk to avoid lumps.

Keep stirring over low heat until the cream thickens.

When you have a thick cream, remove the pan from the heat and pour the cream into a clean bowl. Immediately cover with cling film to prevent skin formation.

Let cool to room temperature and use as desired.