An old-fashioned layer cake conjures a winter wonderland when topped with white-chocolate buttercream as pale and thick as a fresh snowbank. Despite its black-tie formal appearance, this is a very pragmatic dessert because it's even better when you make it in advance: The milk-chocolate pudding in the middle and the icing have plenty of time to set, so the flavors intensify.
You can assemble, frost, and refrigerate this cake, loosely covered, for up to three days. (It's oil-based, so it remains light and tender when chilled, unlike butter-based cakes, which become denser and firmer.) Before serving, return it to room temperature for about 20 minutes