Ingredients:

  • 1 cup (125g) all-purpose flour, sifted
  • 1/2 cup (50g) unsweetened cocoa powder, sifted
  • 1 teaspoon baking powder
  • 1/2 teaspoon baking soda
  • 1/4 teaspoon salt
  • 4 large eggs, separated
  • 3/4 cup (150g) granulated sugar, divided
  • 1/2 cup (120ml) whole milk
  • 1/4 cup (60ml) vegetable oil
  • 1 teaspoon vanilla extract
  • 1/2 cup (120ml) boiling water
  • 1 cup (2 sticks/226g) unsalted butter, softened
  • 3 cups (360g) powdered sugar, sifted
  • 2 tablespoons milk or cream
  • 1 teaspoon orange extract
  • Zest of 1 large orange
  • 8 ounces (225g) semi-sweet chocolate, finely chopped
  • 1 cup (240ml) heavy cream
  • Powdered sugar for dusting
  • Chocolate shavings
  • Sprigs of rosemary or other greenery
  • Edible decorations (e.g., meringue mushrooms, candied cranberries)
  • Cocoa powder for bark effect
  • Marzipan for decoration shapes

Instructions:

  1. Preheat oven to 350°F (175°C). Grease and line a 9x13 inch baking pan with parchment paper.
  2. In a bowl, whisk together flour, cocoa powder, baking powder, baking soda, and salt.
  3. In a separate bowl, beat egg yolks with 1/4 cup of the sugar until pale and thick.
  4. Gradually whisk in milk, oil, and vanilla extract.
  5. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
  6. Stir in boiling water until smooth. The batter will be thin.
  7. In a clean bowl, beat egg whites until soft peaks form. Gradually add the remaining 1/2 cup sugar, beating until stiff, glossy peaks form.
  8. Gently fold the egg whites into the chocolate batter in two additions.
  9. Pour batter into prepared pan and bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
  10. Immediately loosen edges with a knife. Dust a clean kitchen towel with powdered sugar. Invert the cake onto the towel, peel off the parchment paper. Starting from one short end, roll the cake up tightly in the towel. Let cool completely.
  11. While the cake cools, beat butter until light and fluffy. Gradually add powdered sugar, beating until smooth. Mix in milk/cream, orange extract, and orange zest.
  12. Heat heavy cream in a saucepan over medium heat until just simmering. Pour over chopped chocolate in a heatproof bowl. Let sit for 1 minute, then whisk until smooth and glossy.
  13. Carefully unroll the cooled cake. Spread evenly with orange buttercream filling. Re-roll the cake tightly.
  14. Trim off both ends of the log at an angle. Transfer the log to a serving platter. Frost with chocolate ganache.
  15. Drag a fork through the ganache to create a bark-like texture.
  16. Dust with powdered sugar, add chocolate shavings, rosemary sprigs, edible decorations, etc., to create a festive scene. Chill for at least 30 minutes before serving.