225g/8oz plain flour
陆 tsp baking powder
250g/9oz soft light brown sugar or light muscovado sugar
75g/2戮oz golden or white caster sugar
陆 tsp sea salt flakes
1 tbsp vanilla extract
125驳/4陆辞锄 white chocolate, chopped into rough chunks
175g/6oz unsalted butter, plus extra for greasing
2 free-range eggs