There are so many wonderful fillings you can add to your buche de noel! Many people like to use regular vanilla buttercream, but you can also make whipped cream, whipped mascarpone, and so much more. I prefer to use a whipped cream cheese filling because the tartness of the cream cheese cuts through the sweetness of the cake and frosting so well. It's such a nice twist and is my go-to for this gluten-free yule log recipe.