Line a 9-inch square pan with parchment paper, covering edges well to prevent sticking.

In a large saucepan, whisk together granulated white sugar, golden syrup, water, and salt until fully saturated.

Heat the mixture over medium-high heat without stirring until it reaches a gentle boil.

Once boiling, attach a candy thermometer and heat until the syrup reaches 300°F (150°C).

Remove from heat and quickly whisk in baking soda until the mixture expands and becomes frothy.

Pour the foamy mixture into the prepared pan and let it sit at room temperature to harden.

Once cooled, cut the honeycomb into pieces using a sharp knife.

Temper the bittersweet chocolate, dip each piece of honeycomb, and sprinkle with sea salt flakes before the chocolate sets.