220g/8oz plain flour
50g/1¾oz soft dark brown sugar
25g/1oz caster sugar
30g/1oz cocoa powder
1–2 tsp cornflour
1 tsp yeast
50g/1¾oz salted butter, softened
125ml/4fl oz double cream, semi-whipped
1 free-range egg
3 free-range egg yolks
125ml/4fl oz full-fat milk
1 tbsp ground coffee
1 tbsp coffee liqueur