- Make the chocolate mousse: Place small saucepan filled halfway with water over medium heat. Put chocolate in a small heat-proof bowl and place on top of saucepan, making sure the bowl does not touch the water. Let chocolate melt slowly, stirring occasionally. When fully melted, turn heat off, but leave bowl on pot to stay warm.
- In the bowl of a stand mixer fitted with whisk attachment, or with a hand mixer, whip heavy cream to soft peaks. Transfer whipped cream to a bowl and store in the refrigerator until ready to use.
- Clean bowl of stand mixer and whisk attachment. In clean bowl, add egg yolks and whip on medium-high speed. While yolks are whipping, in a small saucepan fitted with a candy thermometer, combine sugar and 1/3 cup water. Stir together so the mixture resembles wet sand. Set over medium-low heat and begin cooking. When sugar reaches between 235 and 238 degrees, slowly stream sugar into egg yolks. Continue whipping until yolks have cooled completely.
- With rubber spatula, transfer whipped yolks into a large bowl. Slowly fold in cooled chocolate, mixing thoroughly. In three batches, gently fold whipped heavy cream into chocolate mixture. Use immediately, or store in covered container in the refrigerator until ready to use.
- Make the roulade: Preheat oven to 325 degrees. Line a half-sheet tray with parchment paper and spray with non-stick cooking spray. Using stand mixer, whip egg whites to medium peaks. Slowly stream 1 cup sugar into eggs. Continue mixing until whites are shiny, glossy, and hold peaks. Transfer to large bowl.
- Clean bowl of stand mixer and whisk attachment. In clean bowl, add egg yolks and remaining cup of sugar. Mix on medium-high speed until light and fluffy. Transfer to the bowl with the whites, but do not mix together.
- Sift flour, cocoa, salt, and cream of tartar together over whipped eggs. Fold everything together with a rubber spatula. Be gentle so as not to deflate the eggs but incorporate all of the flour.
- Pour batter onto three-quarters of parchment-lined sheet tray and spread evenly with an offset spatula. (Any extra batter can be used for cupcakes or to make a small cake.) Bake at 325 degrees for about 10 minutes, or until center is firm. Let cool slightly then, using both hands and starting from the short end, roll cake into itself, like a jellyroll. Allow to cool rolled up for 30 minutes.
- When ready to frost, gently unroll cake and lay flat. Spread the chocolate mousse evenly over top of the cake, leaving a 1-inch border around the edges, and tightly roll again, starting from the short end. Transfer to a baking sheet and refrigerate for at least 1 hour or overnight.
- Make the dark chocolate ganache: Using stand mixer, combine corn syrup, milk, and powdered sugar. Whisk on medium speed until smooth.
- Melt butter in a medium saucepan over medium heat. Once melted, add chocolate and continue heating until the mixture is completely melted. Once melted, pour warm chocolate into milk mixture all at once. Whisk for one minute on low speed to ensure everything is incorporated. Turn mixer to medium speed and mix for 3 minutes. The mixture will appear well emulsified and shiny. Transfer ganache to a bowl or container and allow to set for 2 hours before using.
- To decorate, generously cover the whole cake with ganache. Once it is covered, run a fork all the way through the frosting to simulate the grain of wood. Top with homemade yule log decorations (recipes follow).
YULE LOG DECORATIONS
Makes about 25 mushrooms
4 large egg whites
¼ teaspoon cream of tartar
1 cup granulated sugar
Holly Berries and Leaves Sugar Cookie
- Make meringue: Preheat oven to 250 degrees. Line a cookie sheet with parchment paper or silicone mat. In the bowl of a stand mixer fitted with whisk attachment, whip egg whites on medium speed. When foamy, add cream of tartar and continue whipping to stiff peaks. Slowly stream in sugar while whipping at a medium speed.
- Transfer meringue to a pastry bag fitted a wide tip. Pipe meringues onto prepared cookie sheet: Make two sizes, so one will be the larger top of the mushroom and the other will be the stem. Bake until the meringues are dry and firm, about 1 hour. Let cool completely. Store in parchment-lined, air-tight containers until ready to use
- Assemble mushrooms: Use a small, sharp knife to make a small hole in the bottom of the big meringue, being careful not to go all the way through the top. Set the big meringue on top of smaller meringue, securing the smaller meringue in the cut hole. If it will not hold, add a dab of icing to the top of the smaller meringue to secure.
Makes about 3 dozen cookies
1 cup unsalted butter, room temperature
1 cup sugar
3 cups flour
¾ teaspoon baking powder
¼ teaspoon salt
1 tablespoon milk
Green and red food coloring
- Preheat the oven to 325 degrees. Line a cookie sheet with parchment paper or silicone mat. In the bowl of a stand mixer fitted with paddle attachment, cream butter and sugar until fluffy and light in color. While mixing on medium speed, add the egg and mix until just incorporated. Stop mixer and scrape down sides of the bowl with a rubber spatula. On low speed, add flour, baking powder, salt, and milk. Mix until thoroughly combined.
- Divide dough in half and knead one color dye into each. Wrap doughs in plastic wrap and refrigerate until ready to use.
- Allow dough to come to room temperature slightly. Roll to ½-inch thick and use a cutter to make leaves from the green and berries from the red. Transfer to prepared cookie sheet. Bake at 325 degrees until edges are lightly colored, about 8 minutes. Store extras in an air-tight container for up to 1 week.