Bûche de Noël
Literally translated as "yule log," this traditional French Christmas cake is shaped and decorated to resemble a log. It is made of a sheet of genoise that is spread with mocha or chocolate buttercream, rolled into a log shape and covered with more buttercream. The surface is ridged to resemble the bark of a log and sometimes garnished with meringue "mushrooms" and with "moss" made from chopped pistachio nuts.