Bûche de Noël (Yule Log Cake)

The Bûche de Noel cake is a nineteenth-century French Christmas custom. The cake is modeled after the yule log, which was traditionally burned by households beginning on Christmas Eve. The burning of the yule log represented the coming new year and would bring good fortune to the family. While no one is certain how the yule log became a cake, everyone can agree it's a lovely tradition we don't want to lose.

Ingredients:

For the cake:

• Cooking spray
• 6 large eggs, separated
• 1/2 c. all-purpose flour
• 1/4 c. unsweetened cocoa powder
• 3/4 c. granulated sugar, divided
• 1/4 tsp. kosher salt
• Powdered sugar, for sprinkling

For the filling:

• 1 1/4 c. heavy cream
• 1/4 c. powdered sugar
• 2 tsp. gelatin (optional)
• 1 tsp. pure vanilla extract
• Pinch kosher salt

For the frosting and decorating:

• 1/2 c. (1 stick) butter, softened
• 1 1/2 c. powdered sugar, plus more for garnish
• 5 tbsp. cocoa powder
• 1 tsp. pure vanilla extract
• 3 tbsp. heavy cream
• Pinch kosher salt
• Chocolate curls, for garnish
• Cranberries, for garnish
• Small rosemary sprigs, for garnish

Directions:

• Preheat the oven to 350°F. Line a jelly roll pan with parchment paper and coat with cooking spray. In a medium mixing bowl, combine flour, cocoa powder, and salt.
• In a large mixing basin, whisk the egg yolks until thick. Slowly add 1/2 cup sugar and beat till pale, then add flour mixture.
• In a separate large mixing bowl, whisk the egg whites until soft peaks form. Add the remaining 1/4 cup sugar, a bit at a time, and continue to beat until stiff peaks form. In two batches, gently fold the egg whites into the batter.
• Pour the batter into the prepared pan and smooth it out evenly. Bake for 12 minutes, or until the top springs back when lightly pushed.
• Invert the warm cake onto a clean kitchen towel dusted with powdered sugar. Remove the parchment paper.
• Starting at the short end, tightly roll the cake into a log using the towel. Allow cooling completely.
• To make the filling, place 2 tablespoons of cold water in a shallow microwave-safe bowl and sprinkle gelatin on top in a uniform layer. Allow for 5 to 10 minutes of blooming time, then microwave for 10 seconds, or until gelatin is runny—do not overheat!
• In a large mixing bowl, combine heavy cream, powdered sugar, pure vanilla extract, and a pinch of salt to make medium peaks. If using gelatin, strain and trickle it into the whipped cream while continuing to beat the cream. Place in the refrigerator until ready to use.
• When the cake has cooled, unroll it and evenly pour the filling over it. Roll the cake back into a log, using the towel to aid in the creation of a tight roll. Place seam side down on a baking sheet and refrigerate for 1 hour, or until thoroughly cooled.
• To make the frosting, cream the butter in a large mixing basin until smooth. Beat in the powdered sugar and cocoa powder until no lumps remain, then add the vanilla, heavy cream, and salt.
• Trim the ends and frost the cake with chocolate buttercream when ready to serve. Top with chocolate curls and a little dusting of powdered sugar. To make mistletoe, arrange cranberries and rosemary on a log.