Melt the chocolate in a double boiler. Mix together the yogurt, quark, sugar and egg yolk. Beat the cream and vanilla sugar until stiff and fold in.
Peel and slice the bananas and drizzle with lemon juice. Set aside a few slices for garnish. Pour the rest under the quark cream. Pour the chocolate over it and carefully pull it through with a spoon. Put in a bowl and garnish with bananas.
It`s THE calorie bomb par excellence, but I`ve never had anything left, even though I`ve made twice the recipe!