In a large saucepan heat the honey, water, and sugar. Bring to a boil and simmer on low heat for 5-10 minutes until it reaches brittle stage and a golden color (150C).
Remove pot from heat. Add the baking soda and quickly whisk in for a few seconds. Pour immediately into the cake tin. Leave to set, then break into bite-sized chunks. If it is a humid day, you may have to finish setting in the fridge.