I started making Buche de Noel a few years ago to bring to my husband’s family Christmas dinner. There have been a few variations over the years, including a tasty Ginger Bread cake with Cranberry Jelly and a Spiced Buttercream filling, but none have compared to the Dark Chocolate Mocha version here. Now, at least 2 cakes are required each year – one for his family and one for mine.
The components are fairly simple – chocolate cake, swiss meringue buttercream, chocolate ganache, meringue mushrooms – but it does take some time and patience to pull this cake together. The great thing about this cake is how easy it is to switch up the flavors. The cake can be vanilla if chocolate isn’t your thing, a milk chocolate ganache instead of dark chocolate, peppermint buttercream, the possibilities are endless.
Here is my recipe for the Dark Chocolate Mocha version of this Buche de Noel
Dark Chocolate Mocha Buche de Noel
A classic holiday cake with flavors of dark chocolate and coffee
- FOR THE CHOCOLATE CAKE:
- 1/2 C + 2 Tbsp All Purpose Flour
- 2 Tbsp Corn Starch
- 1/4 C Unsweetened Cocoa Powder (I prefer Hershey's Special Dark)
- 1 tsp salt
- 1 tsp baking powder
- 3 large eggs at room temperature
- 1 C granulated sugar
- 1 tsp vanilla extract
- 1/4 C strong warm coffee (or 1/4 C warm water with 1 Tbsp instant espresso dissolved into it)
- Plenty of confectioner's sugar for sifting
- FOR THE COFFEE BUTTERCREAM:
- 3 large egg whites at room temperature
- 1/4 tsp fine kosher salt
- 3/4 C granulated sugar
- 1/2 tsp vanilla extract
- 1 C (2 sticks) unsalted butter at room temperature
- 1-2 Tablespoons instant espresso powder
- FOR THE DARK CHOCOLATE GANACHE:
- 4oz good quality dark chocolate
- 1/2 C heavy cream
MAKE THE CHOCOLATE CAKE:
Preheat oven to 375 F and prepare a 13x15 sheet pan with parchment and cooking spray. allow a bit of parchment to hang over the longer sides of the pan to assist with removing the cake after it has baked.
Sift together the dry ingredients including the flour, corn starch, cocoa powder, salt, and baking powder.
In the bowl of your stand mixer with the whisk attachment, begin beating the eggs until they start to thicken and turn a pale yellow.
Gradually add the sugar a tablespoon at a time waiting about 20-30 seconds between each addition until the entire cup is incorporated. Continue to beat until the eggs have tripled in volume.
Beat in the vanilla and the coffee until combined.
Remove the bowl from the mixer and gently fold in half the dry ingredients until nearly incorporated. Add the remaining dry ingredients and fold until just combined. A few small streaks of flour are ok.
Gently pour the batter into the prepared pan and spread evenly with an offset spatula. Give the pan a tap on the counter to release any large pockets of air.
Bake for 12-15 minutes until the cake springs back to the touch without sticking to your fingers.
MAKE THE COFFEE BUTTERCREAM:
Set up a double boiler on the stovetop with a very clean heat safe bowl that can nest into a saucepan without touching the bottom of the pan. Bring 1-2 inches of water to a boil in the pan then reduce the heat to a low simmer. Place the bowl on top of the pan ensuring the bottom of the bowl does not touch the water.
Over the double boiler, whisk together the egg whites, salt and sugar. Continue to whisk gently and constantly until the sugar has been dissolved and the temperature of the eggs reaches 160 degrees F. Be sure to keep an eye on the burner temp as well so the water in the pan continues to simmer without boiling.
Transfer the egg and sugar mixture to the very clean bowl of your stand mixer and begin whisking your egg whites into a meringue. The meringue should hold stiff peaks and the temperature should be close to room temp. This can take anywhere from 5-10 minutes.
Change the attachment on the mixer to the paddle attachment and begin incorporating the butter a tablespoon at a time waiting until the last piece has been incorporated before adding the next.
Continue mixing until all the butter has been incorporated. Then increase the speed to medium high until the buttercream is light and airy.
Take a tablespoon of buttercream and put in the microwave for 5-10 seconds until just melted but not hot. Whisk the melted buttercream with the vanilla and espresso powder until fully combined. Use 1 tablespoon of the espresso powder for a hint of coffee flavor or 2 for a stronger flavor.
If your butter cream is too loose, place the bowl into the fridge for 10-15 minutes to firm back up. Beat it again with the mixer before using.
MAKE THE DARK CHOCOLATE GANACHE:
Heat the heavy cream in the microwave till very hot but not boiling.
Finely chop the dark chocolate and add it to the hot cream. Cover with plastic wrap and let sit for 5 minutes.
Uncover and stir until combined and fully smooth with no remaining lumps of chocolate.
Set aside to firm up until it is spreadable like peanut butter.
ASSEMBLE THE CAKE
Lay out a clean linen type kitchen towel that is larger than the pan used to bake the cake. Sift a substantial coating of powdered sugar over the entire towel.
Remove the cake from the oven and run a sharp knife along the edges to release it from the pan. While the cake is still hot, carefully remove it from the pan inverting it on to the towel so that the parchment side is up. Gently remove the parchment and roll the cake from the longer end into a long tube. Be careful not to roll the cake too tightly or you will risk smooshing or breaking it. Allow the rolled up cake to cool to room temperature.
Once cooled, gently unroll the cake. Reserve 1/2 cup of the coffee buttercream and spread remaining on the cake leaving approximately one inch of cake along the long end that was in the center of the roll unfrosted.
Beginning with the unfrosted edge, reroll the cake using the towel to help apply even pressure and create a tight spiral. wrap the cake log in plastic wrap and chill in the fridge for 30 minutes.
Once cooled, trim the edge off one side of the cake to expose your perfect spiral. From the other end cut a piece off the end about 3-4 inches long.
Take that piece you just cut and slice it in half on the diagonal. affix one piece to the side of the cake and one piece to the top of the cake using the reserved buttercream. Loosely cover and place back in the fridge for 30 minutes.
Once fully chilled, use an offset spatula to apply a coating of chocolate ganache to the outside of the cake leaving all of the beautiful spirals exposed. Use the offset spatula to create grooves in the ganache to mimic tree bark. You can also use the tines of a fork for a rougher looking bark.
Keep chilled until ready to serve. See notes below on tips for decorating.
Decorate with things like: meringue mushrooms, a sprinkling of powdered sugar, marzipan holly, sugared cranberries and rosemary