Directions

1. 1

   Preheat your oven to 180°C (160°C fan/gas mark 4). Prepare a 23 x 33cm Swiss roll tin by lining it with baking parchment and lightly greasing with softened butter. Set aside. Ensure your freezer is set to fast-freeze mode and clear space in the coldest section.

2. 2

   In a large bowl, whisk the egg yolks with 140g golden caster sugar using an electric whisk until the mixture is thick, pale and creamy. Sift the cocoa powder over the egg yolk mixture and whisk thoroughly until no lumps remain. In a separate clean bowl, whisk the egg whites until stiff peaks form but they are not dry. Gently fold one-third of the egg whites into the cocoa mixture, then carefully fold in the remaining egg whites in two additions until evenly combined with no visible streaks.

3. 3

   Pour the batter into the prepared tin and gently spread it level with a spatula. Bake in the centre of the oven for approximately 25 minutes, until well risen and just beginning to shrink from the tin edges. Remove from the oven and allow to cool completely in the tin.

4. 4

   While the sponge cools, prepare the ice cream filling. Lay a large sheet of cling film on your work surface. Remove the vanilla ice cream from its tub and place it on the film. Cover with another layer of cling film and quickly work the ice cream into a long sausage shape approximately 33cm long and 5cm wide, working as fast as possible before it softens. Wrap a second piece of cling film tightly around the first and twist the ends securely. Return to the freezer for at least 1 hour to harden completely.

5. 5

   Line a baking tray with baking parchment. Remove the ice cream sausage from the freezer, unwrap it and position it along the centre of the cooled chocolate sponge. Using the parchment to assist, fold the sponge sides up and over the ice cream to enclose it fully. Carefully transfer the roll onto the lined baking tray, positioning the seal underneath. Trim the ends neatly. Cover with cling film and freeze for at least 4 hours, or up to 1 week.

6. 6

   About 20 minutes before serving, prepare the Italian meringue topping. In a saucepan, combine 250g caster sugar with 175ml water. Bring to a rolling boil over high heat and continue boiling until the mixture reaches 115°C on a sugar thermometer.

7. 7

   While the sugar syrup heats, place 2 large egg whites in a large mixing bowl or tabletop mixer and whisk to soft peaks. Once the syrup reaches temperature, slowly and steadily drizzle it into the whisking egg whites while continuing to whisk at high speed. The mixture will gradually thicken and become glossy; continue whisking for about 10 minutes total until the meringue is just warm to the touch. Whisk in the vanilla extract. Use the meringue immediately as it becomes easier to pipe while still warm.

8. 8

   Fit a large piping bag with a 1.5cm star nozzle and fill with the warm meringue. Remove the frozen log from the freezer and carefully transfer it to a serving platter using two spatulas. Pipe the meringue in lines down the length of the log and around the ends, creating an attractive pattern. Using a kitchen blowtorch, carefully scorch the meringue all over until lightly browned and caramelised. Alternatively, bake at 220°C (200°C fan/gas mark 7) for 8 minutes until the meringue is set and lightly golden. Serve immediately in generous slices; the log will hold well for 5-10 minutes at room temperature. Note: This recipe contains lightly cooked egg whites, which may be unsuitable for babies, toddlers, the elderly, pregnant women, and those who are unwell.