1 orange, zest finely grated
1 tbsp fine-shred orange marmalade
150驳/5陆辞锄 plain flour
陆 tsp baking powder
200g/7oz soft light brown sugar
175g/6oz golden caster sugar
25g/1oz cocoa powder
pinch of salt
200g/7oz dark chocolate with orange, roughly chopped
100驳/3陆辞锄 dark chocolate, roughly chopped
250g/9oz dark chocolate chips
225g/8oz unsalted butter, diced, plus extra for greasing
4 medium free-range eggs