Gluten Free Chocolate Swiss Roll

Instructions

1. First, let's make the sponge. Preheat the oven to 180C (fan). Separate the eggs, place the whites in a large mixing bowl and the yolks in a second mixing bowl. Set the yolks aside.
2. Use an electric hand whisk to beat the whites until thick and foamy. Add the caster sugar to the beaten egg whites and whisk again for 3-5 minutes until glossy and you have soft peaks.
3. Beat the yolks together with the milk, until frothy, which will take about 2 minutes. Then add the frothy yolks to the egg whites and sugar before whisking everything together for a couple of minutes.
4. Sift the cocoa, flour and xanthan gum over the frothy mixture. Now use a spatula to fold the dry ingredients into the egg mixture, without knocking out all the air. Fold and scrape at a slow pace, until fully incorporated. The mixture should still be quite mousse-like and full of air.
5. Line a rectangular baking tray (mine is 32cm x 22cm) with greaseproof paper, so that the base and sides are covered. Pour the cake mixture onto the tray and gently spread to the sides and corners using a small palette knife. Bake at 180C for 8-10 minutes, until cooked through - it cooks very quickly. I find 8 minutes is ideal for me, and it's best to err on the side of caution as an overbaked sponge is more likely to crack during rolling.
6. Allow to cool for 2 minutes, then lift out of the tray and onto your work surface. Ease the baking paper away from the sides, to loosen, then on one of the shorter sides of the sponge, fold the excess baking paper over the end of the sponge. This will stop it sticking to itself when rolled. Time to roll! Start from the short end and roll the sponge into a log shape, so the baking paper is on outside of the sponge. Set aside to cool completely, still rolled up (see image below).
7. Once the sponge has cooled, make the chocolate ganache frosting. Finely chop the chocolate and place in a heatproof mixing bowl. Pour the cream over it and then place into the microwave for 1 minute. Then whisk with a fork until you have a lovely, glossy ganache (if you have any lumps of chocolate, give it another 30 seconds in the microwave until they have melted). Note - if your ganache splits or goes hard, do not panic! It is easily rescue - simply add a few drops of boiling water to the ganache, stir and repeat until you have the lovely smooth and glossy ganache you need. Set the ganache aside while you fill and assemble the roll.
8. For the filling, simply mix the mascarpone, icing sugar and vanilla with whisk until smooth. Now add the double cream and beat for about a minute until you have a thick, stiff cream mixture.
9. Carefully unroll the cooled sponge, then spread the mascarpone cream all over the inside. Now roll the sponge up quite tightly, until you have a lovely swirl of chocolate sponge and cream. Trim the edges to neaten slightly - then the perk of being the cook is that you get to eat these bits as a treat :).
10. Place the swiss roll on a wire cooling rack over a piece of baking paper/plate/tray (to catch the ganache run off). Now pour the chocolate ganache all over the swiss roll, ensuring you coat the swiss roll fully. Wait for a minute to let most of the excess drip off, then carefully transfer the roll to a serving plate (I use a palette knife to do this). Now pop it into the fridge to set the ganache for 30 minutes.
11. To finish the roll, melt the white chocolate (I do this in the microwave, in 30 second blasts) and use a spoon or small piping bag to drizzle the molten white chocolate across the chilled swiss roll. To get a nice drizzle, I let the white chocolate cool a little after I have melted it, then use a small piping bag to quickly zig zag back and forth along the length of the roll.
12. The white chocolate will set pretty quickly on the cool ganache, so you can either serve straight away or store it in the fridge until you are ready to enjoy it later.

If you are making this chocolate swiss roll in advance, store it in the fridge to keep it chilled. Same with any leftovers, they should be refrigerated to keep them at their best.