Nothing beats a beautiful and classic bake for the holidays, like these Chocolate Mocha Yule Log Cakes. This recipe makes two yule log cakes from one sheet of sponge; one to give, and one to keep.
This is my first yule log cake of the year, but I love the tradition so much I may post a second one this month. It’s my absolute favorite bake for Christmas, and for me, it’s right up there with making a gingerbread house. Silky-smooth crème au beurre au café (coffee-flavored French buttercream) fills a classic chocolate Swiss roll in these Chocolate Mocha Yule Log Cakes, and both cakes are wrapped in chocolate marzipan ‘bark’.
Swiss roll batter starts with well-whipped eggs. Beat them until they are pale, thick, and when the beater is lifted the batter forms a trail in the bowl. The mixture will deflate slightly when the other ingredients are added, but should still yield a thick yet pourable batter.
Bake the sponge in a 15×11-inch jelly roll pan (or similar size). When done, immediately turn it out and cut it in half so that you have two 7.5 x11 inch pieces. Then roll each half up into a sugar-dusted tea towel starting at a short end and cool completely.
Crème au beurre au café (French coffee buttercream).
While you’re waiting for the sponges to cool, whip up a batch of coffee-flavored whole egg French buttercream. It’s a lot like regular French buttercream, but instead of using egg yolks, you use whole eggs. Get out the ol’ candy thermometer for this one. It’s an extra step but worth it, I promise. Because it’s so silky-smooth and luxurious!
Unroll the sponge and let the most curved end stay curled. Pipe lines of buttercream onto the sponge, spread evenly and then roll it back up. Repeat this process with the second sponge.
Wrap both of the swiss rolls , in a double thickness of waxed paper and then with plastic wrap. The waxed paper helps the cake keep its round shape, and the plastic wrap prevents it from drying out. Refrigerate until firm.
While you wait for the cake to chill, knead some marzipan with unsweet cocoa powder. We’re going to make faux tree bark, and marzipan makes a tasty and beautiful covering.
Tree bark impressions.
First, you’ll need to acquire a tree bark silicone mold, which can be found here. It’s inexpensive and easy to store because it’s flat. Apply some unsweet cocoa powder to the mold to ‘dust’ it before pressing the marzipan. Gently roll the marzipan onto the mold and then turn it out. Trim away the plain edges.
Drape the marzipan over the cake and and fit around the top and sides. It should adhere naturally. But if it seems too dry, brush the cake with a little water before applying the covering. Trim away any excess ‘bark’.
You just can’t go wrong with the flavors of chocolate and coffee together! The silky coffee buttercream is a lovely contrast to the sponge texture. The marzipan tastes mostly of chocolate instead of almond, as the addition of unsweet cocoa will overtake the delicate almond flavor. And that’s preferred for this deeply chocolaty confection!
I opted for a simple presentation without meringue mushrooms (but if you’d like to make some, see this post!). Instead, I used some cute red axe cupcake picks, purchased from Cranky Cakes Shop. Although they are currently out of stock, you can find some for purchase here instead. I think they’re so funny and cute. And they’re perfect with this woodsy cake.
Chocolate Mocha Yule Log Cakes
- 15×11 inch jelly roll pan, or similar size
- Tree bark silicone impression mat
- Axe cupcake picks
- 1/2 cup powdered sugar
- 4 eggs
- 3/4 cup granulated sugar
- 1 tablespoon oil
- 2 tablespoons buttermilk
- 1 teaspoon vanilla extract
- 3/4 cup all-purpose flour
- 1/4 cup dark cocoa powder
- 1 teaspoon baking powder
- 1/2 teaspoon salt
French coffee buttercream
- 1 cup granulated sugar
- 1/3 cup water
- 2 large eggs
- 1 1/2 cups unsalted butter softened
- 3 tablespoons instant espresso powder dissolved in 1 tablespoon hot water
- 1/4 teaspoon fine grain salt
- 14 oz. marzipan
- 1/4 cup unsweet dark cocoa powder plus extra for dusting
- Preheat oven to 350°F. Coat a 15×11 inch jelly roll pan (or similar size) with flour-based baking spray. Alternatively butter the pan and line with parchment paper.
- Lay out two tea towels on a work surface. Sprinkle each tea towel with 1/4 cup powdered sugar and rub sugar into towel with your hands.
- Place eggs in large bowl; beat using electric mixer on high speed, 5 minutes with a timer set. The whipped eggs will become thick and lightened in color. With the mixer still running, slowly add sugar and oil, followed by buttermilk and vanilla.
- In a separate bowl, sift together flour, cocoa, baking powder and salt. Slowly add to the liquid ingredients. Mix until well combined. Pour batter into prepared pan and smooth evenly with a rubber spatula. Bake 12-15 minutes. Cake is done when it springs back when pressed with fingers.
- Immediately turn the sponge sheet out onto one of the sugar-covered tea towels. If you used parchment paper to line the pan, remove it, then cut the sponge in half width-wise so that you have two 7.5 x 11 inch pieces. Roll each cake into a tea towel from a short side. Place the rolled cakes on a wire rack, seam-side down, and let cool completely.
Make the French coffee buttercream
- In a small heavy saucepan set over medium heat, dissolve the sugar in the water. Bring the mixture to a boil, stirring constantly. Continue to cook until it registers 240°F on a candy thermometer.
- In the bowl of a stand mixer with the whisk attachment, beat the eggs until they are thick and pale, about 5 minutes on medium high speed. While mixer is running, add the sugar syrup in a thin stream, carefully tempering the syrup into the eggs without cooking them. Beat until the mixing bowl is cool.
- Change to the paddle attachment and add the softened butter, 1 tablespoon at a time. The mixture will deflate and look runny, then curdled. Keep adding butter and mixing. This buttercream goes through several ugly stages before it reaches fluffy consistency. When all the butter is added, add the espresso mixture and salt. Beat on high speed until light and fluffy.
- Transfer buttercream to a piping bag with 1/2-inch hole cut in the end of the bag.
- Gently unroll a cake, letting the end remain curled. Pipe lines of buttercream over top of cake; spread evenly. Roll the cake back up and wrap in plastic wrap. Repeat with remaining cake and the remaining buttercream. Refrigerate until the frosting is firm, about 1 hour.
- Conservatively trim both ends of the cakes away with a serrated knife so the swirl is visible.
- Knead the marzipan and dark chocolate cocoa powder together until the marzipan is consistently dark brown in color. Dust the tree bark impression mat with cocoa powder using a small kitchen-dedicated art brush to get into all the nooks and crannies of the silicone mat.
- Roll out half of the marzipan on a lightly cocoa-powder dusted work surface. Place it on the impression mat and roll so that the marzipan takes on the tree bark impression; don’t roll too hard or the marzipan will tear.
- Turn the marzipan bark out of the mold and place on top of one of the cakes. Cover the top and sides of the cake entirely, but do not cover the bottom. Trim away excess marzipan. Repeat the process with the remaining cake.
- Cut cake into rounds and add little axe cupcake picks, if using, before serving.
- Serve cakes at room temperature. Store leftovers in the refrigerator. Return cakes to room temperature before serving.