Buche de Noel: Yule Log Cake

I was first introduced to Buche de Noel or Yule log cake by Julia Child via PBS. Later, my uncle Jack, who is a professional baker, sold it each year at his fantastic bakery, The Basque Boulangerie Café, in Sonoma, CA. Buche de Noel is a classic cake, sometimes flour-less, which became popular at Christmastime in France around the turn of the century. Since I stayed in New York for Christmas and wasn't able to have the Basque's delicious cake, I figured I'd give it a try in my own kitchen.

Though the finished product looks like it takes a lot of work, the cake itself is very easy to assemble. It's simply a jelly roll cake that has been frosted and rolled up. I made the cake over several days and assembled everything later. To make it easier, you could leave off the meringue mushrooms and spun sugar and the cake would still be delicious. But if you're feeling ambitious like I was, it can be a lot of fun to go all out. 

Much of the recipe I've provided below was combined from two separate issues of Saveur magazine and were inspired by the famous Paris pastry shop, Ladurée (there is also a New York location at 864 Madison Ave.). I also payed homage to Julia Child and used her recipe for the elegant spun sugar veil. There are many varieties of this tasty log cake, but I like the one I've concocted because it is a chocolate cake or "roulade" with a mocha buttercream filling and finished off with rich chocolate ganache icing. You could certainly do a yellow jelly roll cake instead, but since Aaron and I are chocolate lovers, I had no choice. I was under the weather this Christmas, but had my heart set on this cake, so I made it for New Years instead. It was a very special way to ring in the New Year along side a bottle of bubbly. Happy New Year!

BUCHE DE NOEL:

Adapted from Saveur magazine, issues 39 & 143 and Julia Child, The Way to Cook

Ingredients:

For the meringue:

10 tbsp. sugar

2 large egg whites

2 pinches cream of tartar

Pinch of salt

½ tsp. vanilla extract

¼ cup cocoa powder

½ cup confectioners' sugar

For the roulade:


2 tbsp. softened butter
(for greasing)

8 oz. bittersweet chocolate, finely chopped


1 cup heavy cream


7 egg whites

2 tbsp. sugar


For the mocha buttercream & rum syrup:

1 cup, plus 2 tbsp. sugar

4 egg whites

24 tbsp. (3 sticks) unsalted butter, softened

2 tbsp. strongly brewed espresso

1 tbsp. dark rum (or 1 tbsp. strong coffee or espresso)

For the ganache icing:


12 oz. semisweet chocolate, chopped

8 tbsp. (1 stick) unsalted butter, cut into small pieces


2⁄3 cup heavy cream

For the spun sugar veil (optional):

1 cup granulated sugar

3 tbsp. light corn syrup

1/3 cup water

For the meringue: Preheat oven to 200°. Combine sugar and ¼ cup water in a small saucepan, cover, and bring to a boil over medium-high heat, swirling pan several times until sugar has dissolved, 1–2 minutes. Uncover pan and continue to boil until syrup reaches softball stage or 236° on a candy thermometer, about 4 minutes more.

Put egg whites in the bowl of a standing mixer fitted with a whisk and beat on medium speed until frothy, then add cream of tartar and salt. Gradually increase speed to high and beat until soft peaks form, about 30 seconds. Slowly pour in sugar syrup while continuing to beat until whites cool to room temperature and become thick and shiny, about 5 to 7 minutes. Stir in vanilla. 

Use a rubber spatula to transfer meringue to a pastry bag fitted with a 1/4" plain pastry tip. To make meringue mushrooms, hold pastry tip perpendicular to a parchment paper-lined baking sheet and pipe meringue into the shapes of mushroom caps and stems of various sizes, then set aside for 5 minutes. Lightly moisten a fingertip in cold water and smooth out any "tails" left behind on mushroom caps. 

Bake meringues for 1½ hours. Turn off oven and allow meringues to rest in oven until dry and crisp, about 1 hour. Bore a small, shallow hole in the center of the underside of each mushroom cap with the tip of a paring knife. "Glue" stems to caps by dipping tips of stems into ganache icing, then sticking into holes in caps. Sift a little cocoa powder on tops of caps. Meringues can be stored in an airtight container at room temperature for several days.

For the roulade: Preheat oven to 375 degrees F. Butter a 16½" × 12" heavy baking pan and line with buttered parchment paper, cut large enough to hang over sides of the pan by about 1". Put chocolate in a large mixing bowl and set aside. Bring cream just to a boil in a saucepan over medium heat, then pour over chocolate and whisk until smooth. Set aside to cool.

Beat egg whites in the bowl of a standing mixer fitted with a whisk on medium speed until frothy; increase speed to medium-high and gradually add sugar, beating constantly, then increase speed to high and beat until stiff, glossy peaks form, 30-40 seconds more (careful not to over beat.) Mix one-third of the whites into chocolate using a rubber spatula, then gently fold in remaining whites in two batches, taking care not to deflate batter. Spread in prepared pan and bake until a toothpick inserted in center comes out clean, 10–12 minutes. Set aside to cool in the pan.

For the mocha buttercream and syrup: Place 1 cup sugar and egg whites in the bowl of a stand mixer and set it over a saucepan of simmering water; stir mixture until egg whites register 140 degrees F on an instant-read thermometer. Remove bowl from saucepan and place on stand mixer fitted with a whisk; beat on high speed until meringue is cooled and forms stiff peaks. Replace whisk with paddle and add butter to meringue; beat until smooth, stir in espresso, and set aside. If making in advance, cover with plastic wrap and refrigerate until ready to use. Let come to room temperature before applying to roulade. 

To make the rum syrup, bring remaining sugar, rum (or coffee), and 1 tbsp. water to a boil in a 1-qt. saucepan over high heat; cook until sugar dissolves and set aside to cool.

For the ganache icing: Melt chocolate and butter in the top of a double boiler set over simmering water over medium-low heat, whisking often. Remove from heat and gradually whisk in cream. Transfer to a medium bowl and set aside at room temperature, stirring occasionally, until icing thickens, about 4 hours or overnight (don't refrigerate; it makes icing hard to spread).

For the spun sugar veil (optional): Shortly before serving, bring the sugar, corn syrup, and water to a simmer in a small saucepan. When the liquid is clear and the sugar has dissolved, increase the heat slightly and boil the sugar mixture until the caramel stage on a candy thermometer (320 to 350 degrees F).

Set aside to cool 2 to 3 minutes, until it forms thick strands of sugar when lifted with a fork. Then, dipping the fork into the syrup, wave it over a clean broomstick or large wooden dowel (wrapped in parchment and tied to the dowel using butcher’s twine), to form long hanging threads of sugar. Lift the strands off the broomstick or dowel and gently drape around the Yule log to resemble moss (break off any large stiff globs of sugar and discard).

Assembly: Transfer the cooled roulade with parchment to a clean work surface and brush lightly with rum syrup. Allow syrup to absorb for a few minutes before spreading the mocha buttercream evenly over top using a metal spatula. Grab the long edge of the parchment paper with two hands and gently roll roulade onto itself, pulling off paper as you roll (don't worry if the roulade cracks a little as you roll, as it will be covered by the ganache icing). To make "stumps", diagonally cut a 2" length from each end of buche; then, to make the stumps thinner than the buche, partially unroll each piece, trim off flap, and discard. Set stumps aside.

Using two long metal spatulas, carefully transfer buche to a serving platter lined with strips of waxed paper. "Glue" stumps onto buche with some of the icing. Using a metal spatula, evenly spread icing on buche, dragging spatula along icing to simulate tree bark. Decorate with mushrooms, then sift confectioners' sugar over mushrooms and buche to resemble snow.

Notes:

• Cut waxed paper to cover the exposed ends of the log to keep from drying out. Remove before serving.
• Save the leftover egg yolks to make ice cream.