Mix together the caster sugar and golden syrup in a medium size saucepan until it forms a crumb. While stirring, allow the sugar to dissolve at a medium heat. Once dissolved, leave to gently bubble for approximately 4 minutes.

Remove the saucepan from the heat and immediately fold through the baking soda. Be careful not to overmix, then quickly turn out onto a baking tray lined with grease-proof paper before the mixture solidifies.

Allow to cool, harden and set aside.