1Preparation in advance
Combine custard powder, cocoa and sugar, and stir to a paste with one decilter (1/2 cup) cold milk.
Bring the rest of the milk to a boil, and add the paste while whisking the milk. The custard will have thickened within one minute. Lower the heat and let it simmer for two more minutes while you keep stirring. Pour the custard in a bowl immediately and cover with plastic foil.
Serve with whipped cream.
A friend of mine told me her mother served this with a whipped-creamlike substance of whipped eggwhites mixed with egg yolks whisked with sugar. I don't know what this concotion is called, but it is akin to tiramisu without mascarpone