Double chocolate roll with raspberry and pistachio filling

• butter or oil↗

  for the pan

• dark chocolate↗175g g

  chopped

• eggs↗6 medium
• soft light-brown sugar↗150g g
• sifted cocoa powder

  for dusting

• frozen raspberry↗75g g
• powdered sugar↗3 tbsp tbsp
• double cream↗250ml ml

  plus extra for serving (optional)

• pistachio butter3 tbsp tbsp
• white chocolate↗100g bar g
• dark chocolate↗100g bar g

  (do not use all dark and white chocolate, keep the remainder for another baking)

• pistachios↗50g g

  chopped

Step-by-step instructions

1. 1

   Preheat the oven to 180 °C/160 °C with convection/gas 4. Lightly grease the Swiss roll pan or a sturdy baking tray – ours is 24 × 34 cm – with butter or oil. Line the bottom and sides with parchment paper, making sure the sides are at least 2 cm high. The easiest method is to make a small diagonal cut in each corner of the parchment and fold them into the pan.

2. 2

   Heat water in a small saucepan to a boil, then reduce the heat to minimum and place a heat‑proof bowl on top, ensuring the bowl does not touch the water. Add the chopped dark chocolate and 75 ml of warm water, melt for 5‑10 minutes, stirring occasionally until you obtain a smooth, uniform consistency.

3. 3

   Separate the eggs into two large bowls, add a pinch of salt to the whites and beat with an electric mixer for 4‑5 minutes until the volume doubles and soft peaks form.

4. 4

   Add the sugar to the yolks and beat with an electric mixer (no need to wash it first) for a few minutes to achieve a mousse‑like consistency. Slowly pour in the melted chocolate and beat until homogeneous, about 1 minute.

5. 5

   Using a large metal spoon, fold a portion of the beaten whites into the chocolate yolks and mix to loosen the consistency. Add the remaining whites and gently fold the ingredients, sliding the spoon under the mixture, lifting and turning it while rotating the bowl, until you obtain a fluffy, chocolate‑mousse texture without white‑egg pockets. Be careful not to over‑mix to retain as much air as possible. Pour the mixture into the prepared pan, gently smooth it with a spatula to the edges and level the top. Bake for 18‑20 minutes until a skewer inserted into the centre comes out clean.

6. 6

   Remove from the oven and let cool for 5 minutes. Meanwhile, spread a large sheet of parchment paper on the work surface and dust it with cocoa powder. With one swift motion flip the cake onto the cocoa‑coated surface. Cover with a kitchen towel and let cool for 30 minutes to 1 hour.

7. 7

   Meanwhile, for the filling place the raspberry in a saucepan with 1 tbsp powdered sugar. Bring to a gentle boil over medium heat and cook 2‑3 minutes until juicy. Remove from heat, let cool, then chill in the refrigerator until ready to assemble the roll.

8. 8

   Pour the cream and the remaining 2 tbsp powdered sugar into a bowl. Beat with an electric mixer until the cream forms peaks, about 1‑2 minutes – if too soft they will run off the cake, if too firm they will be hard to spread, so monitor the process.

9. 9

   Remove the kitchen towel from the cake. Folding one of the shorter edges towards you, spread pistachio butter over the surface, leaving a 1‑2 cm margin from the nearest edge. Top with the whipped cream, then spoon the cooled raspberry with its juice. Use the parchment to fold the short edge back onto the cake, then tightly roll the roll, keeping the parchment on the outside throughout and using it to secure the tight roll. Chill for at least 30 minutes. It can be frozen for up to a month.

10. 10

    If the roll is frozen, thaw it in the refrigerator for 24 hours. When ready to serve, unroll the roll. For garnish break off 25 g of white chocolate and melt it in short bursts in the microwave, about 1 minute, or using the same method as step 2. To create chocolate shavings, hold a knife at a 45‑degree angle to the surface of the chocolate bar and pull it towards you. Drizzle the rolled cake with the melted chocolate, then sprinkle milk and white chocolate shavings and scatter the chopped pistachios.

11. 11

    Serve in portions, optionally with extra cream on the side. It can be kept in the refrigerator for up to five days.