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 specialties. 5 December is National Sachertorte Day.
Recipes similar to that of the Sachertorte appeared as early as the 18th century.
Sacher's eldest son Eduard carried on his father's culinary legacy, completing his own training in Vienna with the Royal and Imperial Pastry Chef at the Demel bakery and chocolatier, during which time he perfected his father's recipe and developed the torte into its current form.
The cake was first served at the Demel and later at the Hotel Sacher, established by Eduard in 1876. Since then, the cake remains among the most famous of Vienna's culinary specialties.
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.
According to wikipedia