As of 1945, what is known as a 'bûche de Noël'?

A Yule log, or 'bûche de Noël', is a traditional dessert served near Christmas, especially in Belgium, France, Switzerland, Canada, Lebanon and several former French colonies, as well as the United Kingdom and Catalonia. Made of sponge cake to resemble a miniature actual Yule log, it is a form of sweet roulade.

The original Yule log recipe emerged during the 19th century. It is traditionally made from a sponge cake, generally baked in a large, shallow Swiss roll pan, iced, rolled to form a cylinder, and iced again on the outside.

The most common combination is basic yellow sponge cake and chocolate buttercream, though many variations that include chocolate cake, ganache, and icings flavored with espresso or liqueurs exist.

Yule logs are often served with one end cut off and set atop the cake, or protruding from its side to resemble a chopped off branch. A bark-like texture is often produced by dragging a fork through the icing, and powdered sugar sprinkled to resemble snow.

Other cake decorations may include actual tree branches, fresh berries, and mushrooms made of meringue or marzipan.

The name bûche de Noël originally referred to the Yule log itself, and was transferred to the dessert only after the custom had fallen out of use, presumably during the first half of the 20th century. By 1945, it referred to the cake.