Heather Bertinetti makes a European tradition: a holiday “yule log” made out of chocolate sponge cake and mocha buttercream frosting.
Holiday Chocolate Yule Log Recipe
5 eggs, room temperature, separated
1 cup sugar, divided
1/4 cup cocoa powder
1/2 cup cake flour
1/4 teaspoon salt
1/2 teaspoon cream of tartar
For the Mocha Buttercream:
2 tablespoons instant espresso powder
2 tablespoons rum
4 egg whites
1 cup sugar
1 1/2 cups (3 sticks) unsalted butter, cut into 1/2-inch chunks, softened
1/2 cup powdered sugar
To make the Chocolate Sponge Cake:
Preheat an oven to 350ºF. Prepare a baking sheet by greasing it with nonstick spray, lining it with parchment paper, and then spraying the parchment paper with nonstick spray.
In the bowl of a stand mixer fitted with a whip attachment, beat the egg yolks with 1/2 cup sugar at medium speed until very pale and aerated, 4 to 5 minutes. Transfer the yolks to a large mixing bowl and add the cocoa powder, flour, and salt to the egg yolks, Gently fold them together to incorporate the dry ingredients. Set aside.
In a clean bowl on a stand mixer fitted with a clean whip attachment, whip the egg whites with the remaining 1/2 cup sugar and cream of tartar on medium-high speed until they hold a stiff peak.
Add about 1/3 of the egg whites to the egg yolk mixture and whisk them together to lighten the mixture. Add the remaining egg whites to the bowl and gently fold the mixture together to incorporate the meringue.
Spread the batter evenly onto the sheet pan and bake until the cake is set and dry, 8 to 10 minutes. Cool completely.
To make the Mocha Buttercream:
In a small bowl, stir together the espresso powder and rum to dissolve the espresso. Set aside.
In a medium mixing bowl set over a double boiler, whisk together the egg whites and sugar. Heat the egg whites up, whisking constantly, until they feel hot to the touch. Transfer the egg whites to the clean bowl of a stand mixer fitted with a clean paddle attachment. Whip the egg whites on high speed until they are glossy, hold stiff peaks, and the bottom of the bowl feels cool to the touch.
Swap the whip attachment on the mixer for the paddle attachment and add the butter to the bowl. Beat on medium speed to incorporate the butter into the meringue and slowly stream in the dissolved espresso.
The finished buttercream should have a light, whipped consistency. If it looks a bit “soupy”, place the bowl in the refrigerator for about 10 minutes and gently whip it back together.
To Assemble the Cake:
Lay a piece of parchment paper down on a work surface and generously dust it with powdered sugar. Invert the cake out onto the sheet, discarding the parchment it was baked on. Spread about half of the buttercream evenly over the surface of the cake, leaving a 1/2-inch border around all sides of the cake.
Rotate the cake so that the shorter side is facing you. Using the parchment paper for leverage, roll the cake up on itself into a “jelly roll” shape. Transfer the cake, seam side down, to a serving platter. (note: to create a “stump” on the end of the log, cut a 2-inch piece of cake on a bias off from the end of the log and set it, cut side up, on top of the log)
Frost the roll evenly with the remaining buttercream. Using a kitchen fork, drag the tines through the buttercream from one end of the log to the other to create a textured “bark” look. Refrigerate the cake until ready to serve. Allow the cake to rest at room temperature for about 20 minutes before serving.
Watch Heather assemble the Yule log in her video:
In association with Rachael Ray at www.rachaelray.com