50²µ/1¾´Ç³ú plain flour
70g/2½oz golden caster sugar
1 tsp good quality cocoa powder, sifted, plus extra to decorate
50²µ/1¾´Ç³ú dark chocolate (minimum 70% cocoa solids), broken into pieces
50²µ/1¾´Ç³ú unsalted butter, plus extra for greasing
ice cream or cream, to serve
1 large free-range egg
1 large egg yolk