Put the quark with sugar and vanilla pulp in a mixing bowl. Mix on a low setting for 10 to 15 minutes with the whisk of the hand mixer until creamy. Stir in the whipped cream. Chop the chocolate and melt it with Nutella in a bowl over a hot water bath.
Peel the bananas and cut into slices or cubes, mix with the lemon juice and pour into dessert glasses or a bowl. Fill the nougat mixture on top. Spread the quark cream on top and sprinkle with some grated chocolate.
If you like it a little less substantial, you can of course replace the cream quark with low-fat quark and use Cremefine instead of the whipped cream.