Prepare a baking tin with grease proof paper and set aside.
Place the golden syrup and sugar into a large pot on low heat, stir to combine.
Keep the heat low until sugar has melted (Note: It shouldn't boil or even bubble)
When the sugar has melted increase temperature to medium-low heat. Let it summer slowly until it reaches an amber colour (do not stir at this stage, just make a swirling motion with the pan)
When it reaches that amber colour turn off heat and add in bicarbonate soda.
Whisk vigorously, it will start to foam up and be extremely hot at this stage
Tip it straight into the prepared tin.
Leave it to cool for around 2 hours then break it into chunks and store in an airtight container.