Cut the Viennese base 2x in half. Boil 800 ml of cream together with the chocolate. Then refrigerate for a few hours (preferably overnight).
Then whip with 5 to 6 cream stiffeners until stiff. Now you can also whip the remaining 200 ml of cream with the cream stiffeners until stiff. Spread the chocolate cream between the bases and spread it all around, reserving some cream for decorating. Decorate alternately with the brown and white cream. Sprinkle with shaved chocolate.
Prepared a day before eating, it tastes even better!