A torte (from Italian torta) is a rich, usually multilayered, cake that is filled with whipped cream, buttercreams, mousses, jams, or fruits. Usually, the cooled torte is glazed and garnished.

Sachertorte is a specific type of chocolate cake, or torte, invented by Austrian Franz Sacher in 1832 for Prince Wenzel von Metternich in Vienna, Austria. It is one of the most famous Viennese culinary specialities. The cake consists of a dense chocolate cake with a thin layer of apricot jam on top, coated in dark chocolate icing on the top and sides. It is traditionally served with unsweetened whipped cream. National Sachertorte Day in the US is on the 5th of December.

Hotel Sacher's "Original Sacher Torte" is sold at the Vienna and Salzburg locations of the Hotel Sacher, at Cafe Sacher branches in Innsbruck and Graz, at the Sacher Shop in Bolzano, in the Duty-Free area of Vienna airport, and via the Hotel Sacher's online shop.

The recipe of the Hotel Sacher's version of the cake is a closely guarded secret. That privy to it claims that the secret to the Sachertorte's desirability lies not in the ingredients of the cake itself, but rather those of the chocolate icing. According to widely available information, the icing consists of three special types of chocolate, which are produced exclusively by different manufacturers for this sole purpose. The hotel obtains these products from Lübeck in Germany and from Belgium.

More Info: en.wikipedia.org