100 g (3 1/2 oz) plain chocolate, broken into squares
4 large eggs, separated
100 g (3 1/2 oz) caster sugar
50 g (2 oz) self-raising flour, sifted
300 ml (1/2 pint) double cream
300 g (10 oz) raspberries, plus extra to decorate
cocoa powder, for dusting
Grease and line a 30 x 23 cm (12 x 9 in) Swiss roll tin with nonstick baking paper.
Melt the chocolate in a heatproof bowl over a pan of barely simmering water.
In a large bowl, beat the egg yolks and sugar until pale and creamy. Stir in the chocolate and flour.
Using a clean whisk, beat the egg whites in a separate bowl until stiff peaks form. Carefully fold the whites into the chocolate mixture until well combined.
Tip the sponge mixture into the prepared tin and shake to level it. Bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 15–20 minutes, or until the sponge is slightly risen and just firm to the touch.
Carefully invert the sponge on to nonstick baking paper. Peel the paper from the base of the roulade and discard. Roll up in the fresh paper.
Whip the cream and gently fold in the raspberries.
Unroll the roulade and spread over the raspberry cream, leaving a small gap around the edge. Re-roll the roulade (don’t worry about any cracks). Dust with the cocoa powder, decorate with raspberries, and serve immediately.