Figure 36.
Spread exterior of cake, including stump but keeping ends clean, with thin layer of chocolate buttercream. Refrigerate cake until buttercream is firm, about 15 minutes. Apply thicker final coat of buttercream. (Reserve extra buttercream for assembling mushrooms.) Run tines of fork along the length of the cake to imitate bark. Carefully remove strips of parchment paper. At this point the cake can be refrigerated overnight or frozen for up to 1 month. Cover unfrosted ends with small piece of plastic wrap to protect them from drying out. If freezing, refrigerate until buttercream is firm and then wrap entire log in plastic.