Easy, perfect, delicious and the bonus of being gluten free. This is swirly chocolate chocolateyness...
60g/2 oz plain chocolate, chopped
57g/2 oz butter
4 eggs, room temperature
150g/5 oz sugar
90g/3 oz gluten free flour
1/4 teaspoon xanthan gum
30g/1 oz cocoa powder
1/2 teaspoon baking powder
1/2 teaspoon bicarbonate soda
Two tablespoons icing/powdered sugar
For the filling
150g icing/powdered sugar
150g cold butter, diced
3 tablespoons boiling water
75g cocoa powder
For the coating
200g/7 oz dark chocolate
Preheat your oven to 180C/350F/Gas 4
Line a 10x15"/25x38cm) baking tray with baking parchment
Pop the dark chocolate and butter in a bowl and microwave for 1 minutes, stir then microwave for 30 second bursts, stirring inbetween until melted. Set aside to cool slightly.
In an electric mixer whisk together the eggs and sugar until pale and fluffy and tripled in volume, this will take a few minutes.
Add the chocolate mix gently into the egg mixture and whisk for a few seconds until corporated.
In a separate bowl mix together the flour, xanthan gum, cocoa powder, baking powder, bicarbonate and salt. Add these dry ingredients to the chocolate mixture and gently fold together until there are no lumps.
Pour into the lined baking sheet. Bake for about 10-12 minutes, be careful not to overbake.
Sprinkle the icing sugar over a sheet of baking parchment, laying it on a flat surface.
Remove from the oven and leave in the tin for two minutes then turn out onto the icing sugar covered baking parchment.
Peel off the top layer of baking parchment and use the under piece to roll the sponge up into a swiss roll. Leave it rolled up to cool.
To make the filling, whisk the butter with an electric whisk until pale and soft, this will take a few minutes.
Add the icing sugar and boiling water and whisk again for a couple of minutes until it has doubled in volume.
Add the cocoa powder in, a spoonful at a time, whisking in between. Beat for a further minute to fully combine.
Once the sponge is cool, carefully unroll it and remove the baking parchment. Spread the frosting over the sponge. Gently roll up into a swiss roll.
For the coating:
Break the dark chocolate into pieces and microwave for one minute, stir then microwave for 30 second bursts until it is fully melted. Pour gently over the outside of the swiss roll and spread evenly with a knife. Allow to set.