200g/7oz plain flour
30g/1oz plain flour, sifted
陆 tsp baking powder
50g/1戮oz soft brown sugar
100驳/3陆辞锄 caster sugar
30g/1oz cocoa powder
125驳/4陆辞锄 shelled hazelnuts, ground roughly in a food processor
240g/8陆oz good-quality milk chocolate
pinch salt
125驳/4陆辞锄 dark chocolate (70% cocoa solids)
300驳/10陆辞锄 dark chocolate (75-80% cocoa solids)
175g/6oz butter, plus extra for greasing
125驳/4陆辞锄 unsalted butter
2 free-range eggs, 1 whole, 1 yolk only