Orange-Walnut Buche De Noel How-To 1. Carefully roll up the cake again, and position it seam side down on a parchment-lined baking sheet. Spread the rest of the filling over the top of the log. 2. Arrange the chocolate "bark" all over the cake, pressing gently and overlapping pieces slightly; work as quickly as you can to avoid melting. Refrigerate until firm, at least 1 hour.