Mix the caster sugar and syrup in a deep saucepan with a splash of water and simmer over a gentle heat until the sugar has melted.
Once completely melted, turn up the heat and boil until you have an amber coloured caramel.
Then, as quickly as you can, turn off the heat, tip in the bicarbonate and beat in with a wooden spoon until it has all disappeared and the mixture is fluffy, foaming and bubbling. Pour on the baking paper immediately but be careful as the mixture will be very hot.
Let the honeycomb rest until it is hard and ready to crumble or snap into chunks. Store in an airtight container for maximum a week.
Stuff to know
Do not overcook the caramel or it will be too bitter. The easiest way to clean the saucepan is by boiling some water in it to dissolve any remaining caramel. Add spices to the caramel, like ground cinnamon.
Recipe by Jeroen Valkenier Recipes at https://jpvalkenier.com/honeycomb/