Chocolate Bûche de Noël

Instructions

To make the chocolate ganache filling: Pour the cream into a medium heavy-bottomed saucepan and set over medium heat, stirring with a wooden spoon, until small bubbles form around the edges of the pan. Remove from the heat and add the chocolate. Allow to sit for 5 minutes, then stir the chocolate into the cream. Add the vanilla and salt and slowly stir with a wooden spoon until smooth. Set aside to cool.

Additional Notes:

Plastic chocolate molds in star shapes are available in craft stores. Follow the directions that come with the mold to make the stars.

Instructions

Set an oven rack to the middle position and preheat to 350°. Coat the bottom and sides of an 11-by-17-inch rimmed metal jelly roll pan with vegetable oil spray. Line the pan with parchment paper, and coat that with more vegetable oil spray.

In a small bowl, whisk together the flour, cocoa, baking powder, and salt. Set aside.

Put the egg whites in the bowl of a stand mixer fitted with the whisk attachment and beat until firm peaks form (you can also use a handheld mixer). If you have only one mixer bowl, transfer the beaten egg whites to another bowl and set aside.

Put the egg yolks, 1 cup granulated sugar, and water in the bowl of the stand mixer fitted with the paddle attachment; beat until pale yellow. Beat in the vanilla. Add the dry ingredients to the egg-sugar mixture in two additions and stir until combined. Remove the bowl from the stand and fold the egg whites into the batter in three additions. Pour the batter into the prepared pan and level with an offset spatula. Bake until the jelly roll just begins to pull away from the sides and springs back to the touch, about 20 minutes. Do not overbake, or the roll may crack.

While the roll is baking, wet a dish towel with water, wring it out, and dust generously with the remaining 1/2 cup of granulated sugar. Turn the roll onto the prepared dish towel, and carefully peel the parchment paper from the roll. Trim off any crispy edges on the roll.

Gently roll up the warm roll from one wide end, using the towel so that the cake doesn’t stick to itself but is rolled up with the towel where the filling would be. Tuck the towel under the bottom of the roll, allowing it to stay in place until the roll has cooled, about 30 minutes.

Unroll the cooled roll, removing the towel. Spread the cooled ganache over the entire surface with an offset spatula. Reroll the roll carefully and transfer to a serving platter by picking. Store the roll in the refrigerator until ready to decorate.

Instructions

Put the butter, confectioners’ sugar, and salt to the bowl of a stand mixer fitted with the whisk attachment and beat together. Add the vanilla and continue to beat. Add the cooled chocolate to the mixture and beat until the mixture is light and fluffy. Add the water, one tablespoon at a time, and mix until the frosting is the desired consistency.

Remove the jelly roll from the refrigerator. Place sheets of wax paper on either side to keep the serving platter clean. Cover the entire roll with frosting, except for the ends and the bottom. Run the tines of a fork through the frosting to form a barklike texture. Trim both ends at the same angle. Dust with the finely ground pistachios. Place chocolate stars randomly over the top. Place in the refrigerator until ready to serve. The roll is fragile and should be eaten the day it is baked; any leftovers should be kept refrigerated.

For garnish:
1/2 cup pistachio nuts, finely ground in a food processor
Chocolate stars or other decorations (see note)