Step 1. Preheat the oven to 190C/170C Fan/Gas 5 and line a 9x13in Swiss roll tin with baking paper
Step 2. Add the eggs, sugar and 1tsp of your vanilla extract into a bowl. Whisk until very pale, fluffy and thick – this could take a few minutes
Step 3. Sift in the flour and carefully fold in. Pour the mixture into the lined tin and evenly spread. Pop in the oven for 10–12 minutes, or until just firm to the touch
Step 4. Place a sheet of baking paper, larger than your baked sponge, onto a work surface and sprinkle some of your extra caster sugar on top. Turn the sponge out onto the paper and peel off the baking paper on the bottom of the sponge, you then need to let this cool a little
Step 5. Pour the double cream and remaining vanilla extract into a bowl and whip it until you get soft peaks
Step 6. whipped cream over the top, leaving the same gap, then sprinkle over some whole raspberries or strawberries depending on your taste!
Step 7. Take the longest edge of the sponge and using the baking paper underneath, roll up the sponge quite tightly. Roll the sponge off the parchment, dust with extra caster sugar and you’re done!
Step 8. Cut into generous slices and enjoy