01 -
Preheat oven to 350°F (175°C). Line a 10x15-inch jelly roll pan with parchment paper and lightly grease the surface.
02 -
In a large bowl, beat egg yolks and granulated sugar with an electric mixer until thick, pale, and creamy, about 3 minutes. Blend in vanilla extract.
03 -
In a separate bowl, sift together cake flour, cocoa powder, baking powder, espresso powder, and salt.
04 -
Fold the dry mixture gently into the whipped yolk mixture until just combined.
05 -
In a clean bowl, whip egg whites until stiff peaks form. Take care not to overbeat.
06 -
Gently fold egg whites, one third at a time, into the cake batter, maintaining as much volume as possible.
07 -
Spread batter evenly in prepared pan. Bake for 10–12 minutes, or until sponge springs back when lightly touched.
08 -
Immediately invert warm cake onto a clean kitchen towel dusted with confectioners' sugar. Peel away parchment and, starting at short end, roll up cake with towel. Cool completely, seam side down.
09 -
In a chilled bowl, beat heavy cream, confectioners’ sugar, and vanilla until stiff peaks form. Refrigerate until needed.
10 -
Place chopped chocolate and salt in a heatproof bowl. Heat 3/4 cup heavy cream in a small saucepan until steaming but not boiling. Pour over chocolate; let stand 2 minutes. Add butter and vanilla, then stir until smooth and glossy. Cool until slightly thickened and spreadable.
11 -
Unroll cooled sponge cake, discard towel. Spread whipped cream evenly over cake, leaving a 1/2-inch border. Gently roll cake back up without towel.
12 -
Place filled log seam side down on a serving platter. Spread ganache over the surface, using an offset spatula to create a bark-like texture. Optional: Use a fork to create wood grain effects on the surface.
13 -
Chill assembled yule log in the refrigerator for at least 1 hour before slicing to allow ganache to set.