This is the Yule log cake I made for Christmas dinner. Since it was almost twice as long as my mom's silver cake tray, I just cut the rolled up cake in half and made it into two logs. The recipe is from a Julia Child cookbook, and was a bit more complicated and detailed than I'm used to. For the cake, a browned butter-citrus genoise, I was supposed to beat the eggs (without separating them, which surprised me) with the sugar for 5 minutes while I browned the butter. Unfortunately, the butter took more than 5 minutes to brown, and by the time it had finished cooking and cooling, the eggs had severely deflated. I'm afraid that was the reason the cake remained flat and dense rather than becoming springy in the oven. However, it wasn't a disaster - it still tasted fine, even though the texture was wrong, and it actually rolled up much more easily than the lighter-textured cakes I've made for Buches de Noel past.
The filling and frosting, which I made the day before I made the cake, were a challenge as well, but one in which I was more successful. They're based on Italian meringue, which I'd never tried to make since it involves bringing sugar water to the soft-ball stage and drizzling it into whipped egg whites, a process that seemed to hold way too many opportunities for disaster. However, it actually worked, to my amazement. Without a candy thermometer, I had to stand over the saucepan of bubbling syrup, dribbling drops from the end of a spoon onto a saucer until they seemed to make a ball-like droplet, but I guess I got it right. After adding the sugar, I had to add melted chocolate and butter, then separate into two bowls, one to become filling (with an extra half stick of butter beaten in), the other to become frosting (with a few tablespoons of cocoa added to stiffen it up). I made the mushrooms out of marzipan painted with melted white chocolate and dusted with cocoa. When I had frosted the cake, I made bark designs with the tines of a fork and sifted confectioners' sugar over everything for snow. It looked beautiful, and was a light and sweet finish to a day of feasting.