Whisk the milk, sugar, egg, cornflour, vanilla and icing sugar in a sauce pan. Let boil while stirring and simmer for 2-3 minutes until creamy texture.

Remove from the heat and stir down the chocolate and butter. Stir until fully melted and well mixed.

Pour in portion sized glasses and cover with cling foil to avoid skin. Cool in fridge for about an hour, until the pudding is cold.

Serve with whipped cream.

* Adjust the amount of cacao to taste.