450g (1lb) Soft Brown Sugar
225g (8oz) Black Treacle
110g (4oz) Unsalted Butter
2 tbsp Water
1 tbsp White Vinegar
Put the butter, water and vinegar into a saucepan and heat under a gentle heat until the butter has melted.
Add the sugar and black treacle and allow to fully dissolve, this takes roughly 20 minutes.
Boil the mixture to a temperature of 138°C (280°F).
Remove from the heat and leave until it stops bubbling.
Pour the mixture into a oiled 18cm (7 inch) sandwich tin.
When the mixture has cooled a little mark the surface into squares with a knife.
When cold break into squares, wrap in cellophane and store in an airtight container.