The tradition comes from a very long time ago, even before one started to eat log shaped cake for Christmas. Long ago, a huge log was placed in the fireplace after being blessed to protect the house and its inhabitants (and sometimes sprinkled with oil or wine as an offering) and then burned for the occasion of Christmas Eve. The log had to be big enough to smolder overnight (and even up to Epiphany day, 12 days later in some regions!). Choosing the type of wood, the log itself, and who will place it in the fireplace or light it was of greatest importance. It is even said that ashes or the firebrand who had served were supposed to protect (from thunder, devil …). Traditions varied from one region to another (and even from one family to another).
Fire places became smaller and smaller, and cities bigger and bigger, making this tradition quite unease to respect. Logs burned in fireplaces were replaced by even smaller, sometimes decorated, placed as a table centerpiece. It is then that started to appear cakes with the shape of a wood log, even imitating bark.
As for many dishes, several stories last. Was it an invention from the Parisian pastry chef Antoine Caradot located rue de Bucy in 1879? Or from another based in the city of Lyon earlier in the 1860s? Or from Prince Charles III of Monaco’s ice cream and pastry chef, Pierre Lacam in 1898?
Nevertheless, the symbolic cake substituting wood log was quickly a success and tradition changed from a real log to a fake log, our now classic Yule log. Since the beginning, Christmas yule logs were made with Genovese sponge cake (baked in a particular mold before the cake started to be rolled up) and buttercream, already with decorations (holly, leaves, mushrooms ….). The first flavors were probably chocolate or mocha.
I hope this story interested you.