For the black and white chocolate mousse, first prepare the black part. To do this, chop the chocolate into small pieces, pour into a large enough bowl and melt in a hot water bath. Separate the eggs. Let the chocolate melt in the water bath. Allow chocolate mixture to cool to lukewarm.
Whip the cream until semi-stiff. Beat egg whites with 10 g sugar until creamy and firm. First fold in the whipped cream in two portions, then stir the whipped cream into the chocolate, and finally carefully fold in the remaining egg whites. Let stand at room temperature until the white mousse is ready.
For the white mousse, chop the chocolate into small pieces and melt over a hot water bath. Soak gelatin in enough cold water to soften.
Remove chocolate from water bath and fold in yogurt. Squeeze gelatine, melt in 2 tablespoons of hot whipped cream in a small saucepan and stir into the chocolate. Whip the cream until semi-stiff. Beat the egg whites with the sugar until creamy. First fold the whipped cream into the chocolate two at a time, then the snow.
Alternately fill black and white chocolate mousse into precooled glasses or glass bowls (if necessary, put the glasses in the refrigerator in between so that the individual mousse layers become firm and do not mix). Finish with a white mousse layer and smooth. Refrigerate for at least 2 hours to set. The black and white chocolate mousse to the S