125²µ/4½´Ç³ú caster sugar
25g/1oz cocoa powder, sieved
100g/3½ oz self-raising flour
1 tsp vanilla extract
300²µ/10½´Ç³ú dark chocolate, broken into pieces
125²µ/4½´Ç³ú baking spread or soft butter, plus extra for greasing
150ml/5fl oz double cream
2 large eggs
150ml/5fl oz full-fat milk