Ingredients:

  • 4 whole Large Eggs, room temp (separated)
  • ½ cup + 2 tbsp Granulated Sugar (for sponge)
  • ½ cup All-Purpose Flour, Sifted
  • 3 tbsp Unsweetened Cocoa Powder, Sifted, high quality
  • ¼ tsp Fine Sea Salt
  • 3 large Large Egg Whites (100 g), room temperature (for buttercream)
  • ¾ cup Granulated Sugar (150 g) (for buttercream, caster sugar preferred)
  • 1 cup Unsalted Butter (2 sticks/225 g), room temp, Cubed
  • 2 tsp Strong Coffee or Espresso Powder (dissolved in 1 tbsp hot water)
  • 1 tsp Pure Vanilla Extract
  • 6 oz Dark Chocolate (70% cocoa), Finely chopped
  • ¾ cup Heavy/Double Cream (180 ml)
  • Confectioners’ Sugar (Icing Sugar), As needed (for dusting)
  • Optional Decorations (Meringue mushrooms, cranberries, rosemary sprigs)

Instructions:

  1. Preheat the oven to 175°C (350°F). Line a 10 x 15 inch rimmed baking sheet with parchment paper, allowing an overhang on the long sides for easy lifting.
  2. In a stand mixer, whisk the 4 combined egg yolks and 4 egg whites with sugar on high speed for 5–8 minutes until very pale, thick, and the batter falls in a 'ribbon' that holds its shape briefly. This incorporates the air needed for lift.
  3. Sift the flour, cocoa powder, and salt together over the egg mixture. Gently fold with a spatula until just combined. Do not overmix, or the cake will deflate.
  4. Pour the batter into the prepared pan and spread evenly to the edges. Bake for 10–12 minutes until the sponge springs back lightly when touched. Immediately upon removal from the oven, turn the warm cake out onto a clean, large tea towel dusted lightly with cocoa powder or icing sugar. Peel off the parchment paper. While still warm, tightly roll the cake and the tea towel together from the short end. Place the rolled cake seam-side down on a wire rack to cool completely for at least 30 minutes.
  5. Combine egg whites and sugar in a heatproof bowl placed over a saucepan of simmering water (Bain-Marie). Whisk constantly until the sugar is dissolved and the mixture reaches 70°C (160°F) or is hot to the touch.
  6. Transfer the hot mixture to the mixer and whisk on high speed until stiff, glossy peaks form and the outside of the bowl is completely cool to the touch (this is the Swiss meringue).
  7. Reduce speed to medium-low. Gradually add the cubed, room-temperature butter, piece by piece, continuing to mix until the mixture emulsifies into a smooth, thick buttercream. Beat in the dissolved coffee/espresso powder and vanilla extract.
  8. Gently unroll the cooled cake. Spread ¾ of the Mocha Buttercream evenly over the surface, leaving a ½ inch border. Re-roll the cake tightly (without the towel). Wrap the log in cling film or foil and chill for at least 2 hours to set the filling.
  9. Using a sharp serrated knife, slice off the ends of the cake for a clean finish. Cut a 1-inch thick diagonal piece off one end of the log and affix this smaller piece (the 'branch') to the side or top of the main log using a little reserved buttercream.
  10. Place chopped dark chocolate in a bowl. Bring the heavy cream to a simmer and pour it over the chocolate. Let it sit for 5 minutes, then whisk until smooth and glossy. Let the ganache cool until it reaches a thick, spreadable consistency (about 30–60 minutes at room temperature).
  11. Cover the entire log, including the end caps, with the ganache. Use the tines of a fork or the tip of an offset spatula to drag through the ganache, creating deep grooves that mimic the texture of tree bark.
  12. Chill the decorated log for 30 minutes until the ganache is set. Dust heavily with confectioners’ sugar just before serving for the 'fresh snow' effect.