Black Forest Bouche de Noel

I wanted to make a traditional Buche de Noel last year, inspired by this incredible cake by Sprinkle Bakes, and I used her recipe for the Swiss roll. I never got to it last year, but I made my first yule log this year with black forest flavors. I think it turned out wonderfully, with a perfect tight spiral and fantastic meringue mushrooms. I want to improve upon the cherry flavor, which I think would have been amplified had I used kirsch. I opted not to use kirsch because of children wanting to eat the cake.

It was impressive enough that my son has now requested this as his birthday cake for next year ... we'll see. He said the same thing about the pumpkin churro cake I made, so I'm on a roll.

There's lots of steps, but the meringues can be made and stored for several days, which helps a lot.

Black Forest Bouche de Noel
Swiss Roll
4 eggs
3/4 cup (150 grams) sugar
1 Tbsp. oil
2 Tbsp. buttermilk
1 tsp. vanilla
3/4 cup (90 grams) flour
1/4 cup (25 grams) cocoa powder
1 tsp. baking powder
1/2 tsp. salt
1/4 cup (30 grams) powdered sugar
Whipped Cream
2 Tbsp. granulated sugar
1 tsp. cornstarch
1 cup cold heavy cream
1 tsp. vanilla
Chocolate Buttercream Frosting
1 cup salted butter
3 1/2 cups powdered sugar
1/2 cup cocoa powder
3-5 Tbsp. heavy cream
2 tsp. vanilla
Meringue Mushrooms
2 egg whites, room temperature
1/4 tsp. cream of tartar
75 grams sugar
Cocoa powder for sprinkling

To Make the Cake
Preheat oven to 350°F. Butter a 15 x 10-inch jelly roll pan, and line with parchment paper.

Place eggs in a large bowl, and beat 5 minutes. With mixer 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 the liquid ingredients. Mix until well combined. Pour batter into prepared pan, and smooth it evenly with a rubber spatula. Bake 12 to 15 minutes. Cake is done when it springs back when pressed with fingers.

Sprinkle a tea towel with powdered sugar, and rub sugar into the towel with your hands. Immediately turn cake onto the sugar-covered towel. Peel off the parchment paper, and roll cake into the tea towel, beginning at the narrow end. Place rolled cake on a wire rack, seam-side down, and cool completely before filling it.

To Make the Whipped Cream
To prepare the whipped cream, place the sugar and cornstarch in a small pan. While stirring constantly, pour in 1/4 cup cream. Place pan over medium heat, and bring it to a boil while stirring constantly. Remove from heat, stir in vanilla and cool completely. Meanwhile, place remaining cream in mixer bowl, and refrigerate.

Once the cornstarch and cream mixture has cooled, whisk the pure heavy cream on medium until tracks begin to show in the cream. With mixer still on, slowly add the cornstarch mixture, and continue whisking until stiff peaks form. Refrigerate until ready to assemble cake.

To Make the Cherries and Syrup
Drain the cherries, reserving the syrup. Simmer the syrup over medium heat until it is reduced to 1/3 cup. Remove from heat, and stir in kirsch and lemon juice.

Cut cherries in half, and set aside on paper towels to soak up some of the extra moisture.

To Make the Frosting
Beat the butter on high speed 3 to 5 minutes to incorporate plenty of air. Gradually add powdered sugar and cocoa ,and beat until smooth. Continue beating, while adding vanilla and then heavy cream until desired consistency is reached.

To Make the Meringue Mushrooms
Preheat oven to 225°F. Whisk the egg whites with the cream of tartar until soft peaks form. Then whisk in the sugar one tablespoon at a time until meringue is stiff and glossy. Transfer to a large piping bag with a large nozzle. Pipe 8 mounds 5 centimeters wide. Dip your finger in cold water, and gently smooth any peaks as these are the mushroom caps. Then pipe cones about 2 centimeters high for the stems. Sprinkle with cocoa powder to create a mushroom effect.

Bake 70 minutes, and then turn off the oven without opening the door. Cool completely in the oven, even overnight.

To assemble mushrooms, melt a small amount of chocolate in the microwave. Use that chocolate to adhere the stems to the caps. (I like to place mine in the refrigerator to set quickly.) You may need to shave off part of the stems to get them to fit well.

To Assemble Cake
Gently unroll cake. Use a pastry brush to spread the cherry syrup evenly across the cake, allowing it to absorb into the cake. Gently spread the whipped cream evenly on top of the cake, leaving about 1 inch on the far end of the cake roll, where it will be be last rolled (so all the filling doesn't ooze out). Sprinkle evenly with cherries. Carefully roll cake tightly, and place seam side down. Frost, and use a knife to create texture the long way to replicate a log. Decorate with mushrooms, and sprinkle with powdered sugar if desired. Keep refrigerated until one hour before serving. Slice carefully with a sharp knife, cleaning the knife between cuts for beautiful spiral slices. Serves approximately 16.