1. Preheat Oven & Prepare Pan:

• Preheat oven to 350°F (175°C).

• Line a 10×15-inch jelly roll pan with parchment paper, greased and floured.

2. Make the Cake:

• In a large bowl, beat eggs and sugar together with an electric mixer on high speed for about 5 minutes, until thick and pale.

• Beat in vanilla.

• Sift in cocoa powder, flour, baking powder, and salt, then gently fold in until just combined.

• Pour batter into prepared pan and spread evenly.

3. Bake & Roll:

• Bake for 10–12 minutes, or until the cake springs back lightly when touched.

• Remove from oven, let sit 1 minute, then carefully turn the cake out onto a clean kitchen towel dusted with powdered sugar.

• Peel off parchment, then roll the cake with the towel (from short side). Let cool completely.

4. Make the Filling:

• In a chilled bowl, beat heavy cream, powdered sugar, and vanilla until stiff peaks form.

• (Optional: add mascarpone for thicker filling.)

5. Fill and Re-roll Cake:

• Unroll cooled cake. Spread whipped cream filling evenly over surface.

• Re-roll gently (without towel). Place seam-side down on a tray.

6. Make Ganache:

• Heat cream in a small saucepan until just simmering.

• Pour over chocolate and let sit for 1–2 minutes. Stir until smooth and glossy. Let cool slightly to thicken.

7. Decorate:

• Spread ganache over the log. Use a fork to create bark-like texture.

• Dust with powdered sugar for “snow.”

• Optional: decorate with mushroom meringues, rosemary sprigs (for “pine”), or sugared cranberries.