Chocolate and vanilla swiss roll

Method

1. Preheat the oven to 200C (fan 180C, gas mark 6).

2. Grease a 23cm x 33cm swiss roll tin with butter and line with baking parchment.

3. With an electric mixer, whisk together the eggs and sugar until pale and thick and holds a trail when the whisk is lifted.

4. Divide the mixture in half into two bowls then sieve 45g flour in to one and very gently fold it in with 1/2 tbsp of hot water.

5. Sieve the remaining flour (30g) and the cocoa powder into the other half and gently fold in with 1/2 tbsp hot water with the milk.

6. Spoon the two mixtures into to separate disposable piping bags.

7. Snip the end off the piping bags so they pipe a 1cm trail. With the short side of the tin facing you pipe alternate stripes on the diagonal until the whole swiss roll tin has been covered.

8. Bake in the preheated oven for 7 - 8 minutes until springy to the touch, being careful not to overcook.

9. Dust a large piece of baking parchment with caster sugar and turn the sponge immediately out onto it, carefully remove the baking parchment that it has been cooked on and cover with a slightly damp tea towel for 5 minutes to cool.

10. Meanwhile make the buttercream icing by whisking together the icing sugar, vanilla bean paste and butter until light and fluffy.

11. Remove the tea towel and making sure it is cool enough so the icing doesn’t melt, spread the icing evenly over followed by the jam.

12. Make a slight indent about 1cm in from the short end, and carefully roll up the swiss roll tightly using the baking parchment to help, finishing with the seal underneath.