Break the chocolate into pieces and place in a bowl with butter. Melt in a hot water bath while stirring occasionally. Separate the eggs. Gradually stir egg yolks, brandy and icing sugar into the chocolate cream.
The correct consistency is reached as soon as the mixture falls off the spoon with a heavy tear. Beat the egg white until stiff. Stir 1/3 of it into the chocolate cream with a whisk. Fold in the remaining beaten egg white with a dough scraper.
Pour cream into a bowl and chill for about 2 hours. Whip the cream until stiff and fill into a piping bag with star-shaped spout. Garnish cream with cream patches and chocolate leaves and dust with cocoa powder.