A bûche de noël, literally a Christmas log, is an elaborate rolled cake decorated with chocolate buttercream to look like a log. It can be as simple or as elaborate as you like. Meringue mushrooms are a classic decoration for this dessert; you can also use marzipan leaves, berries, and stems.
Cut the ends off the rolled cake (the log) at an angle and attach them to the sides of the log with buttercream so they look like branches on the side of the log. Coat the log with buttercream, then use a metal spatula to make lengthwise streaks to simulate bark. Arrange the meringue mushrooms on the log. Decorate with marzipan leaves, berries, and stems.
Assembling a bûche de noël
Cut both ends off the rolled cake at a 45-degree angle, approximately.
Dollop a mound of the chocolate buttercream near one end of the log and slightly to the side.
Place one of the end wedges over the buttercream and apply more buttercream around the base of the end, holding it in place.
Repeat with the other end piece at a different position on the log.
Use a small offset spatula to apply the rest of the buttercream. Form flat streaks to simulate bark.
Arrange the meringue mushrooms on the log.
Decorate the log with strands of marzipan (stems) and marzipan leaves and berries.