Mix pudding powder and sugar, stir with 50 ml milk until smooth. Bring 450 ml milk to the boil in a saucepan, remove from the heat, stir in the pudding powder. Bring to the boil again while stirring and simmer over a low heat for about 1 minute
Take off 1/3 of the mass and mix with the cocoa powder. Layer light and dark pudding alternately in 4 glasses and marble lightly with a fork. Decorate each pudding with 1 tablespoon of chocolate shavings