White chocolate roulade

Pre-heat the oven to 180C/160C Fan/Gas 4. Line a 25cm x 38cm swiss roll tin with baking paper. Melt the chocolate in a bowl over a pan of simmering water but don't let the bowl touch the water. Leave to cool for 10 minutes.

Separate the egg whites and yolks into 2 large bowls. Whisk the whites to stiff peaks. Add 25g of the caster sugar and whisk again. Then whisk the yolks with 150g caster sugar until thick and pale – the whisk should leave a trail when lifted.

Whisk the chocolate gently into the yolk mixture then fold in the whites. Transfer to the tin and bake for 20 minutes or until the top feels springy. Cover with 2 clean tea towels, leave to cool for 10 minutes, then wrap cling film around the sponge, tin and tea towels and cool on a rack for at least 6 hours – this will make the roulade easier to roll.

Decorate just before serving. Lightly beat the egg white in a bowl and sprinkle caster sugar onto a plate. Roll the raspberries, one at a time, in the egg white, then dip in the sugar to get a frosted effect.

Turn out the roulade on to a sheet of baking paper dusted with caster sugar. Peel off the lining paper then trim each edge of the sponge to neaten. Whip the cream until it holds its shape and spread half of it over the top. Scatter with the rasberries. Roll up the sponge, using the paper to help. It may crack, but don't worry – it will still look and taste fantastic.

Put the roulade on a serving plate and cover with the remaining cream. Dust the top with cocoa powder, arrange the chocolate stars, then serve.