The Hotel Sacher's specialty of the house is a dessert invented by who?
Franz Sacher
Title: Sachertorte
Passage: 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.
Title: Hotel Sacher
Passage: The Hotel Sacher is a five-star hotel located in the Innere Stadt first district of Vienna, Austria, vis-à-vis to the Vienna State Opera.  It is famous for the specialty of the house, the Sachertorte, a chocolate cake with apricot filling.  There is also an art gallery in the hotel with works from the 19th century.  The hotel is built near the former residence of Antonio Vivaldi.
Title: Double skin milk
Passage: Double skin milk (Cantonese: 雙皮奶, soeng1 pei4 naai5) is a Cantonese dessert made of milk, egg whites, and sugar.  It was first invented in Shunde, Guangdong.  It is a velvety smooth milk custard somewhat resembling panna cotta, with two skins.  The first skin is formed during cooling of the boiled milk and the second when cooling the cooked custard.  Traditionally buffalo milk is used; its higher fat content compared to cow's milk produces a smooth texture.  This dessert is particularly famous in Shunde, Guangzhou, Macau, and Hong Kong.
Sachertorte Hotel Sacher