Preheat the oven to 350°F (177°C) and line a 10"x15" baking sheet with parchment paper. Whip the egg whites in a large bowl until soft peaks form and set aside.

Whisk the egg yolks and granulated sugar in a separate large bowl until pale yellow and well combined, then add vanilla and whisk again.

Sift together the cake flour, cocoa powder, baking powder, espresso powder, and salt in a medium bowl. Add the dry ingredients to the egg yolk mixture and stir to combine.

Add half the whipped egg whites to the batter and stir vigorously. Gently fold in the remaining egg whites.

Pour the batter into the prepared pan and smooth the surface with a spatula. Bake for 10-12 minutes until spongy and springs back when touched.

Prepare a clean kitchen towel by sprinkling it lightly with powdered sugar.

Let the cake cool for a minute on the tray, then carefully invert it onto the sugared towel and peel off the parchment paper. Starting at one short end, roll the cake up gently with the towel inside. Let cool completely seam side down.

While the cake is baking, place chopped chocolate, butter, vanilla, and salt in a heatproof bowl. Heat the heavy cream in a saucepan over low until it bubbles at the edges.

Pour the hot cream over the chocolate mixture and let sit for 5 minutes. Stir until smooth and combined, then let cool or refrigerate.

Whip the heavy cream using a mixer until soft peaks form. Add confectioners' sugar and vanilla, then continue whipping until stiff peaks form.

Once the cake is completely cooled, carefully unroll it and spread an even layer of whipped cream filling over the surface, leaving about ½ inch at the edges clear.

Gently re-roll the cake without the towel and place it seam side down on a serving platter. Optionally, slice one end at an angle and place it next to the log.

Coat the outside of the cake roll with the chocolate ganache on all sides. Create log-like textures using a fork or toothpick.

Let the ganache set briefly. Garnish with fresh cranberries, rosemary sprigs, and a dusting of powdered sugar. Slice and serve.