The recipe for a modern pastry test came from another court cook, Marie Antoine Karem. Marie-Antoine Karem is rightfully considered one of the founders of modern world cuisine. He was the court chef of Napoleon I, worked in England for George IV. Karem served as a cook even in Russia, where in a few short months he organized a real gastronomic revolution at the court of Alexander I.
French confectioners believe that ideal eclairs should be 14 centimeters long, the same and even. Fill them usually with a custard: vanilla, chocolate or coffee.