1. Lightly oil an 18cm shallow square tin. Measure the Tate & Lyle Fairtrade sugar and water into a large heavy based pan. Heat gently until the sugar has dissolved. Add the rest of the ingredients and bring to the boil.
2. Using a clean pastry brush, brush the inside of the pan with cold water just above the level of the mixture, then bring to the boil. Boil rapidly for 10-15 minutes or until the temperature reaches the soft crack stage or 143C. The easiest way to test is the toffee has reached 143C is to use a sugar thermometer. Alternatively, drop a little of the mixture into a bowl of cold water and if the syrup separates into threads which are hard but not brittle, it is ready.
3. Pour into the tin, cool for 5 minutes and if wished mark into squares with an oiled knife, and leave to set in a cool place (but not in the refrigerator). Or just leave to set and break up with a toffee mallet for irregular shaped pieces.