Yule Log Cake

1. Preheat the oven to 355 degrees F (180 degrees C). Grease a jelly roll pan. Line it with parchment paper, and grease the paper.

2. Beat 1/2 cup plus 2 tablespoons sugar and egg yolks until light and fluffy. Add 3/4 cup plus 1 tablespoons flour, butter, lukewarm water, and baking powder; beat until well combined.

3. Beat egg whites and salt in a glass, metal, or ceramic bowl until stiff. Transfer 1/3 of the whites to the cake batter and gently fold in. Repeat with remaining whites. Spoon batter into the prepared pan and spread evenly.

4. Bake in the preheated oven until it springs back when pressed gently in the middle, about 12 minutes. Remove from the oven and let sit in the pan for 3 minutes, before carefully turning the cake out onto a large piece of parchment paper. Roll the parchment and cake from one short end to the other and let cool.

5. While the cake is cooling, place chocolate for buttercream in the top of a double boiler over simmering water. Stir frequently, scraping down the sides with a rubber spatula to avoid scorching, until chocolate is melted, about 5 minutes. Remove from the heat.

6. Beat softened butter in a bowl until light and creamy. Add powdered sugar in small increments, beating between each addition. Add melted chocolate and beat until well combined.

7. Carefully unroll the cooled sponge cake. Spread a thin layer of buttercream across the top to the edges. Firmly roll back up, using parchment to help you, into a tight roll.

8. At one end of the roll, cut off a diagonal slice to represent a branch, about 2 inches in length at the longest side. Frost the entire roll with buttercream. Use a palette knife to create uneven ridges to represent tree bark. Position the branch somewhere near the center of the log and cover with buttercream.

9. Drag the tines of a fork lengthwise across the buttercream to create an extra bark effect. Dust the entire log with cocoa powder.

Editor's Note:

The original recipe is in metric. If you have a scale, the metric measurements are: 125 g sugar, 60 g unsalted butter, and 100 g flour for the cake. For the chocolate buttercream you will need 100 g chopped chocolate, 150 g unsalted butter, and 200 g powdered sugar.