A Slice of Christmas

Tradition and innovation converge in France's festive bûche de Noël.

By Gabriella Gershenson

Bûche de Noël (Yule Log Cake with Coffee Buttercream and Ganache)

Credit: Todd Coleman

Paris at Christmastime is heaven for a cake lover like me. True, a pâtisserie on virtually every street corner is seductive at any time of year, but there's something magical about windows packed with elaborately decorated bûches de Noël. Few French people celebrate Christmas without one of these cakes, a sponge roulade filled and iced with buttercream in flavors such as coffee, praline, chocolate, and chestnut. Modeled after the Yule log, the bûche is typically decorated with such embellishments as meringue mushrooms, marzipan holly, stumps whorled in a wood grain pattern, and frosting that's scored to resemble bark.

I adore these traditional gâteaux. Yet over the last decade, I've noted a mounting trend: New interpretations of the bûche de Noël are proliferating; shapes and decorations have departed from the classic log; textures and flavors have grown markedly lighter, fruitier, and more adventurous. Strolling past the Montmartre pastry shop of Arnaud Delmontel some Christmases ago, I noticed a selection of bûches in a range of Technicolor hues: a glossy sea foam–green roulade of pistachio sponge and mousse, with a sour cherry core; another in school bus yellow that was flavored with yuzu, the Asian citrus that seems as common as chocolate in Parisian pastry these days. They were devoid of stumps and meringue mushrooms, yet they were still, clearly, bûches de Noël. These whimsical departures made me wonder about the evolution of this iconic cake. Spurred by my curiosity, last winter I contacted Delmontel, who offered to show me how he prepares a bûche de Noël à la crème au beurre café, the version he believes is at the root of the tradition.

Christmas is an exceptionally busy time for Delmontel, who owns three pastry shops in Paris. He starts planning his seasonal offerings in June, developing recipes and creating brochures to showcase his collection. In early December, he displays the cakes in his shops' windows. Closer to the holiday, he sets up a tent outside for those who have preordered. In the two weeks before Christmas, the chef and his team produce close to 2,500 bûches de Noël.

The key to making a great bûche de Noël, according to Delmontel, a stocky man with a silver ponytail, is mastering the sponge cake, or as it's called in French, biscuit: "If it's cooked correctly, the cake is already done." He began by making a meringue, beating it until it was glossy and stiff enough to form a bec d'oiseau, or bird's beak, when the whisk was pulled from the bowl. Mixed into the biscuit batter, the meringue helped produce a cake that was springy to the touch and flexible enough to roll. For the coffee buttercream, Delmontel mixed more fluffy meringue, coffee extract, and soft butter until the cream took on a satiny sheen.

Once the cake had baked and cooled, Delmontel brushed on a coffee-flavored syrup, waited a few minutes for it to absorb, and then spread buttercream over the cake from edge to edge. To form the log shape, he rolled the cake and sliced off the ends on the bias, arranging the "stumps" on top of the log. Using a pastry bag, he piped on more buttercream, covering the exterior of the cake. Finally, he warmed a fork in hot water and slashed bark-like markings through the frosting. He cut me a slice, and I took a bite. My mouth filled with bittersweet coffee essence and silky buttercream; the sponge was delicate, yet kept the whole thing grounded. It was simply one of the most delicious cakes I could hope to eat.