Yule log is a memorable dessert for the holiday table, but forget the heavy chocolate kind; this lighter, more stylish one has a nut meringue and a mascarpone and passion-fruit filling. The nuts in the meringue are interchangeable, so although this is made with almonds, you could use hazelnuts or walnuts, if you prefer. The rich filling is mellowed by the brightness of the passion fruit and the tartness of the lime zest. You can surround it with Christmas decorations to make it look festive or sift icing sugar over both the tray and the dessert for a falling-snow effect.