Brush four ovenproof moulds (capacity 125 millilitres) with the butter and spread the brown sugar in them. Bring the milk to the boil. Mix eggs, sugar and vanillin sugar. Add the hot milk while stirring.
Pour the egg milk into the moulds and let it stand in a water bath in a preheated oven (electric cooker 150 ° C/ gas: level 1) for 60 minutes. Remove and let cool off. Turn out onto plates and sprinkle with pistachios.
Serve decorated with cocktail cherries and mint.