Joanne Harris, Fran Warde
1 hr 15
By Joanne Harris and Fran Warde
This two-tone cake combines two kinds of chocolate for a melting contrast of flavours. Topped with chocolate curls, it makes a spectacular Yule log or celebration cake.
Heat the oven to 180°C/gas 4.
Line a 36cm x 25cm tin with baking parchment. First make the roulade. Break the chocolate into pieces and melt in a bain-marie (that is, in a heatproof bowl over a pan of simmering water).
Place the butter and sugar in a bowl and whisk until c