Preheat the oven to 150 ° C top / bottom heat. Brush the muffin tin (12) with butter and set aside.
Drain the mandarins in a colander.
In a bowl, stir the quark, egg, vanilla sugar, sugar and milk until smooth. Divide the filo pastry sheets into 9 equal pieces and place in 4-5 layers in the muffin molds and press down a little. Put 1 tablespoon of quark mixture on each. Put the mandarins on top. Bake in the oven on the lowest rack for about 20 to 25 minutes. Let cool down a little and sprinkle with powdered sugar.
A treat while still lukewarm. It is best to bake twice as much at the same time.