For the mousse, roughly chop the chocolate and melt it in a hot water bath. Let it cool down.
Finely puree dates and milk with a hand blender (or in a blender jug). Whip the cream until stiff. Stir the quark with the whisks of the mixer until smooth. First stir in the date mix, then the slightly cooled, still liquid chocolate. Carefully fold in the cream. Pour the mousse into six glasses (each containing approx. 200 ml). Chill for about 1 hour.
For the cocoa syrup, meanwhile, bring rice syrup, cocoa, 2 tablespoons of water and vanilla extract to the boil in a small pot. Let it cool down.
To serve, remove the pomegranate seeds. Coarsely chop the pistachios. Serve the mousse with cocoa syrup, pomegranate seeds and pistachios.