Bûche de Noël

My mom always used to make Buche de Noel for Christmas, and this year she passed the torch to me.  I am glad I made a rolled cake this summer - it made this recipe a lot less intimidating.  There are quite a few components to put together, but just tackle it one step at a time, and it's not overwhelming.  I made the syrup first, then the filling, chilled it, then baked the cake, and while it was cooling, made the buttercream.  Last, I put together the mushrooms and dusted the whole thing with cocoa powder.  Make sure you start the recipe a few hours in advance, as the components all take time, and the roll must chill for 4 hours before being frosted.

My dad just bought a Nikon D60, and he graciously let me borrow it to take pictures of this dessert.  The difference between his and my little old camera is striking!

(adapted from Jacques Torres's A Year In Chocolate by Jacques Torres, seen on Serious Eats)

First, make the syrup:
-makes 1 1/2 cups-
Ingredients
1 1/4 cups water
2/3 cup sugar
2 1/2 tablespoons Kahlua

Procedure
1. In a small, heavy-bottomed saucepan, combine the water and sugar, place over medium-high heat, and bring to a boil, stirring occasionally. When the sugar has dissolved completely, remove the pan from the heat. Transfer to a heatproof bowl and let cool completely.
2. Stir the liqueur into the cooled syrup. Use immediately, or store, tightly covered, in the refrigerator almost indefinitely.

Next, make the Chocolate Pastry Cream:
-makes about 2 cups-
Ingredients
4 tablespoons sugar
1 tablespoon cornstarch
2 large egg yolks, at room temperature
1 cup whole milk
1/2 vanilla bean, split in half lengthwise
3 1/2 ounces semisweet chocolate

Procedure
1. Sift together 2 tablespoons of the sugar and the cornstarch in a bowl. Whisk in the egg yolks until well blended, thick, and smooth.
2. In a heavy-bottomed nonreactive saucepan, combine the milk with the remaining 2 tablespoons of sugar. Using the edge of a small, sharp knife, scrape the seeds from the vanilla bean into the milk and then add the bean. Place over medium heat and bring to a boil, whisking occasionally. Remove from the heat.
3. Whisking constantly, whisk about one-third of the hot milk mixture into the egg mixture. Pour the combined mixtures into the hot milk mixture, whisk to combine, and return to medium-low heat. Cook, whisking constantly to keep the mixture from sticking and burning. Just before the mixture comes to a boil, it should thicken enough to coat the back of a spoon. As soon as the mixture boils, lower the heat slightly and continue to whisk for another 2 minutes to cook out the raw taste of the cornstarch and allow the flavors to mellow.
4. Remove from the heat and strain through a fine-mesh sieve into a clean bowl. Cover with plastic film, pressing it directly on the surface to keep a skin from forming, and let cool to room temperature.
5. Place the chocolate in the top half of a double boiler. Place over (not touching) gently simmering water in the bottom pan and heat, stirring occasionally, until completely melted. Using a rubber spatula, fold the hot chocolate into the cooled pastry cream. Cover with a piece of plastic film until ready to use. If not using immediately, refrigerate for up to 24 hours.

Third, make the Cake:
Ingredients
2 large eggs, at room temperature
2 large egg yolks, at room temperature
1/3 cup plus 2 tablespoons granulated sugar
1 1/2 teaspoons whole milk
2 large egg whites, at room temperature
1/3 cup cake flour
1/4 cup confectioners’ sugar

Procedure
1. Preheat the oven to 425 degrees F. Line a 15 1/2–by—10 1/2—by 1—inch baking sheet (jelly-roll or quarter sheet pan) with parchment paper and grease it.
2. In the bowl of a stand mixer fitted with the whip, combine the whole eggs, egg yolks, 1/3 cup of the sugar, and the milk and beat on medium-high speed for about 6 minutes, or until the mixture is very light and has tripled in volume.
3. Place the egg whites in a bowl and, using a handheld mixer, whip on medium speed until foamy. Add the remaining 2 tablespoons sugar a tablespoon at a time and continue to beat. When the sugar has been incorporated, raise the speed to medium-high and whip for about 5 minutes, or until stiff, but not dry, peaks form.
4. Using a rubber spatula, gently fold about half of the whole egg mixture into the egg whites. When almost incorporated, fold in the remaining half, taking care not do deflate the batter.
5. Place the flour in a fine-mesh sieve and, tapping on the side of the sieve, sift the flour over the meringue batter. Using a rubber spatula, gently fold the flour into the batter, making sure the spatula reaches to the bottom of the bowl to ensure an even mixture.
6. Scrape the batter into the prepared pan, and use an offset spatula to spread it evenly. Don’t press down too hard, or the pressure will cause the batter to deflate.
7. Place the confections’ sugar in a fine-mesh sieve and, tapping on the side of the sieve, sift the sugar evenly over the surface of the batter.
8. Bake for about 5 minutes, or until the cake just begins to brown on the edges. Remove from the oven and immediately run a paring knife around the inside edge of the pan to loosen the cake sides. Place a sheet of parchment paper over the top of the cake, and then invert a cookie sheet over the parchment. Immediately invert the cake and the cookie sheet together, then lift off the baking sheet. Peel the parchment paper off the cake. Let cool completely.

While the cake cools, make the Coffee Buttercream:
-makes about 3 cups-
Ingredients
3 large egg yolks, at room temperature
1 large whole egg, at room temperature
Scant 1 cup sugar
1/3 cup water

1 tbsp instant espresso
1 1/2 cups (3 sticks), at room temperature, cubed

Procedure
1. In the bowl of a stand mixer fitted with the whip, combine the egg yolks and whole egg and beat on medium-high speed for about 7 minutes, or until tripled in volume and very thick, light, and airy.
2. In a heavy-bottomed saucepan, combine the sugar and water. Clip a thermometer to the side of the pan, place the pan over medium-high heat, and bring to a boil. Boil for about 12 minutes, or until the mixture registers 250 degrees F. When the sugar syrup is ready, remove it from the heat. With the mixer on low speed, carefully pour the hot syrup between the ship and the side of the bowl, taking care not to hit the whip as you pour, or the hot syrup will spatter and burn you.  Add the instant espresso. Beat on medium-high speed for about 3 minutes, or until the outside of the bowl is warm but not hot and the mixture is slightly cool.
3. Add the butter and continue to whip on medium speed for a couple of minutes, or until the butter is incorporated. Raise the speed to medium-high and beat for about 10 minutes, or until thick, smooth, and shiny, and well emulsified.  Be careful not to overbeat, or the buttercream will be grainy.
4. Use immediately, or cover tightly and store in the refrigerator for up to 3 days.

To make the mushrooms, you will need about 3 ounces of almond paste or marzipan, and a few teaspoons of cocoa powder.  Roll a few pieces of marzipan into a ball, then press a small indentation into one side (this will be the mushroom cap).  Roll a few other pieces into cylinders for the stems.  Press the stem into the indentation, then dust with cocoa powder.  Repeat for as many mushrooms as desired.

To put it all together:
1. Line a cookie sheet with parchment paper. Place the cake on a clean, flat work surface with a long side facing you.
2. Drizzle the Kahlua syrup evenly over the cake, using just enough to moisten but not soak the cake.
3. Spoon the pastry cream on top of the cake and, using an offset spatula, carefully spread the cream evenly over the cake, taking care to spread it evenly up to the edges.
4. Starting at the long end farthest from you, slip your fingers between the parchment and the cake and begin rolling the cake toward you, up and over the pastry cream, until you have a firm log shape, or roulade.
5. Carefully transfer the roulade, seam side down, to the prepared cookie sheet. Cover with plastic film and refrigerate for at least 4 hours to allow the roulade to set.
6. Transfer the roulade to a serving platter. Using a serrated knife, cut a 1 1/2—inch—thick slice from one ends of the roll. This will be used to form a “gnarl” on the finished log.  If your log is too long to fit on your platter, cut a 5" pice on a diagonal, and use it to form a branch off the longer piece.
7. Using an offset spatula, generously coat the entire log with all but about 1 cup of the buttercream, spreading from left to right in long streaks. Place the reserved slice on top of the log,  a little off center. Pull a fork or cake comb through the buttercream on the cake so that it resembles tree bark. Place in the refrigerator for about 15 minutes to allow the buttercream to set.
8. Remove the cake from the refrigerator. Dust the cake with a little cocoa powder. Arrange the mushrooms around the cake.