Chocolate Vanilla Buche de Noel

Another Christmas, another Buche de Noel, or Yule log.
This year I have mixed a couple of past recipes, improved on the buttercream, and well...it was pretty good!

Chocolate Vanilla Buche de Noel

Serves 12

For the cake:
6 large eggs
1/4 tsp cream of Tartar
3/4 cup sugar
1/3 cup cocoa powder + 1 Tbsp

Vanilla buttercream:
5 large egg whites
1 cup sugar
1 vanilla bean, split lengthwise and scraped
1/3 cup water
1 lb butter, cut into cubes, room temperature


Chocolate ganache:

8 1/2 ounces bittersweet chocolate, chopped
300 g heavy cream (1 1/4 cup)

50 g butter (1/2 stick)

5 cl liqueur (your choice!) - I used Scotch for this recipe

Prepare the vanilla buttercream:

Combine the egg whites and 1/3 cup of sugar in the bowl of a stand mixer fitted with the whisk. Scrape in the seeds from the vanilla bean - you can keep the empty bean in your sugar container. The sugar will take in the flavor for your next dessert recipe!

Combine the remaining ingredients in a medium saucepan. Stir over medium heat until the sugar dissolves. Increase the heat and boil until a candy thermometer reaches 238F to 240F, about 5 minutes. Remove from the heat and use within 2 minutes.

While the sugar is getting to desired temperature, whisk the egg whites on medium speed until soft peaks form. the mixture will be slightly opaque.

Increase the mixer speed to high and slowly pour in the hot syrup down the sides of the bowl and beat until meringue forms stiff peaks. Let cool to 100F. Do not beat.

Start beating meringue again on medium speed and add the butter, gradually. Make sure butter gets incorporated completely before adding more pieces.

Continue beating until smooth.
If the buttercream gets curdly or appears broken, reheat slightly and beat again).



Make the Cake:
Preheat the oven to 350F. Butter a 15x10x1 - inch jelly roll pan, or a cookie sheet. Line the bottom with parchment paper, allowing a 1-inch overhang on the short sides. Butter and flour the paper.

In the bowl of an electric mixer fitted with the whisk, beat the egg whites until foamy. Add the Cream of Tartar and whisk until soft peaks form. Add 6 Tbsp of sugar and whisk until stiff peaks form. Set aside.

In another bowl, beat the egg yolks with 1/3 cup cocoa powder and the remaining 6 Tbsp of sugar until thick, about 2 minutes. Stir in 1/4 of the egg whites to lighten the batter. Fold in the remaining whites. Gently spread the batter in the prepared pan.

Bake the Genoise until the cake springs back when you press the center, about 15 minutes. Transfer pan the rack and let cool completely.

Unmold on a slightly humid kitchen towel. Peel off the parchment paper.
Sift remaining cocoa powder over the cake and roll tightly, lenghtwise. Set aside.

Now prepare the ganache:

In a medium heavy saucepan, heat the cream. Add the chocolate, butter and liqueur. Whisk and remove from the stove. Let cool, whisking regularly. The chocolate mixture should thicken, but not become too hard. 

Assemble the Yule Log:

Unroll the cake and dust with cocoa powder. Spread the vanilla buttercream evenly on the cake and, using the towel as an aid, roll the cake lengthwise (this time the towel should not be inside the cake!!).
When rolled, cut about 2 1/2 inches off both sides, diagonally, and place one piece on top of the cake, slanted side down, and the other on the side, slanted side against the main body of the cake. This should look like a wood log!

Spread the ganache on the cake, in an irregular fashion, and decorate with meringue mushrooms and other Christmas decorations.


Note:
For the buttercream, if the meringue has not cooled enough, the cream will become runny. Place the bowl on a bag of ice cubes and whisk; it should regain proper consistency.

Note2:
It is a good idea if you like the biscuit a little more moist to brush it with an aromatic syrup (sugar and water and a liquor) before spreading the filling.