Ingredients:

  • 4 large eggs, separated
  • ¾ cup granulated sugar
  • ½ cup all-purpose flour
  • ¼ cup unsweetened cocoa powder
  • 1 tbsp vegetable oil
  • 1 tbsp milk
  • ½ tsp vanilla extract
  • Pinch of salt
  • 1 cup (2 sticks) unsalted butter, softened
  • 3 cups powdered sugar
  • ½ cup unsweetened cocoa powder
  • ¼ cup milk
  • 1 tsp vanilla extract
  • 2 tablespoons rum or coffee liqueur (optional)
  • Powdered sugar for dusting
  • Chocolate shavings
  • Meringue mushrooms
  • Fresh cranberries
  • Rosemary sprigs

Instructions:

  1. Line the baking sheet with parchment paper, ensuring it overhangs the sides slightly for easy removal.
  2. Whisk egg yolks and sugar until pale and thick. In a separate bowl, whisk together flour, cocoa powder, and salt. Gradually add the dry ingredients to the wet ingredients, alternating with the oil and milk. Stir in vanilla extract. In a clean bowl, beat egg whites until stiff peaks form. Gently fold the egg whites into the chocolate batter.
  3. Spread the batter evenly onto the prepared baking sheet. Bake until the cake springs back when lightly touched.
  4. Immediately invert the cake onto a clean kitchen towel dusted with powdered sugar. Gently peel away the parchment paper. Roll the cake up tightly in the towel, starting from one of the short ends. Let it cool completely.
  5. Beat the softened butter until light and fluffy. Gradually add the powdered sugar and cocoa powder, alternating with the milk. Stir in vanilla extract and rum (if using). Beat until smooth and creamy.
  6. Unroll the cooled cake. Spread a generous layer of chocolate buttercream evenly over the cake. Re-roll the cake tightly.
  7. Trim the ends of the log with a serrated knife. Frost the entire log with the remaining buttercream, creating a rough, bark-like texture with an offset spatula. Decorate with powdered sugar, chocolate shavings, meringue mushrooms, cranberries, and rosemary sprigs.
  8. Chill for at least 30 minutes before serving.