Chocolate Swiss Roll with Chocolate Ganache

For the cake:
Preheat oven to 450 F. Line a 12 x 17 inch baking pan with parchment paper. Grease it and dust it lightly with cocoa powder.

In a small bowl, whisk cocoa powder, cake flour and salt. Set aside.

Put eggs, egg yolks and 1/2 cup sugar in a mixing bowl over a pot of simmering water. Use an electric hand mixer to beat constantly until the sugar has completely dissolved and mixture is warm to touch. Remove from heat.

With whisk attachment, continue whipping the mixture in a standing mixer on high until pale and thick, about 4 minutes.

Sift the cocoa mixture into the egg mixture and fold it in gently. When almost incorporated, pour the melted and cooled butter down the side of the bowl, gently folding to combine.

Pour the batter into the prepared pan. Spread the batter evenly. Bake for 6 to 7 minutes, or until springy to touch.

While the cake is baking. Place a clean dish towel on your working surface. Dust the towel with cocoa powder.

Immediately upon removing the cake from the oven, invert it onto the towel you have prepared. Remove the top parchment paper carefully. Then roll the cake while it’s still hot. Let it cool completely (wrapped in the towel) .

Beat the heavy cream until soft peaks form, then add the remaining tablespoon of sugar and continue beating until firm.

When the cake is completely cool, unroll the cake, and top it with the cream.

Re-roll the cake without the towel. Wrap the towel around the rolled cake and tighten it lightly. Refrigerate for 30 minutes.

To prepare the ganache, place the chocolate pieces in a heatproof bowl. Set aside. Heat the cream and butter in a small saucepan over medium heat until just boiling. Immediately pour the boiling cream over the chocolate and allow to stand for 5 minutes. Stir gently with a spoon until smooth.

Before serving, pour the ganache onto the centre of the cake roll. Working quickly, spread the ganache with a large metal spatula or knife, using big strokes to push the ganache over the sides of the cake.