90驳/3录辞锄 plain flour
150g/5陆oz light brown sugar
300g/10陆oz golden caster sugar
65驳/2录辞锄 cocoa powder
170驳/5戮辞锄 dark chocolate (minimum 70% cocoa solids), roughly chopped
170驳/5戮辞锄 unsalted butter, diced, plus extra for greasing
3 free-range eggs