Our yule-log challenge this year: Create a twist that not only holds up nicely in the freezer (even when iced and decorated!), but tastes delicious—and just a little bit different. Mission accomplished, thanks to white-chocolate whipped cream and clementine slices that you confit, like a pro, in your microwave. If you decide to assemble this bûche the day of, you can still get a jump on a couple of steps: Both whipped cream and candied citrus will keep well in the refrigerator for a few days.