The conceit is carried further by mounding the cream over small pieces of cake stuck to the main roll, to represent trimmed branches.
The ends of the roll and the cut faces of the branches are finished with vanilla cream, imitating pale newly cut wood, and the whole is decorated with leaves made from icing, or meringue mushrooms." ---Oxford Companion to Food, Alan Davidson, [Oxford University Press: Oxford] 1999 (p.
There were plenty of ailments in northern Europe for which sugar was considered suitable treatment--coughs, colds, chest infections, agues. Thomas Aquinas himself apparently considered and pronounced on the subject), which meant it could be legitimately nibbled during Lent, probably adding to its appeal.
It is no coincidence that our earliest information about pulled-sugar sweets in Britian, using the very word penides that travelled all the way from the Orient, comes from compilations of medicinal formulae, not elegant books on fine confectionery.
Put the remaining butter cream in a pastry bag fitted with a flat cannellated tip.
Force the cream lengthwise over the surface of the cake to give the appearance of bark. Decorate the cake with almonds and a sprig of holly made with strips of angelica and little rounds of candied cherries. Food historians tell us that hard candies (sticks, losenges, etc.) were originally manufactured for medicinal purposes.
Buche de Noel is one of many traditional cakes baked at Christmas. The name of this recipe literally translates as "Christmas log," referring to the traditional Yule log burned centuries past.
The ingedients suggest the cake is most likely a 19th century creation.184) Buche de Noel recipe sampler  "Buche de Noel.--Gateau symbolique qu l'on prepare chez tous les patissieres de France, a l'occasion de la fete de Noel.Cette buche se fait generalement avec des abaisses de genoise fine, qu l'on fourre avec des cremes diverses (le plus souvent, une dreme au beurre), qu l'on faconne en forme de buche, et que l'on decore a la poches munie d'une couille cannellee, avec une creme au beurre aux chocolate ou au moka qui cimule l'enorce de al buche. Tracer les stries de la buche avec une fourchette." --- Le Livre de La Patisserie: Recettes Practiques, editions du cep [E. 141-2)  "Yule Log (Buche de Noel) The yule log cake is served at the midnight feast that follows Mass on Christmas Eve.Spread the cake with the butter cream and roll it up lenghthwise like a jelly roll.Place seam side down on a long serving tray and cut off both ends diagonally.We find no person/place/company credited for having *invented* this particular confection.