prep: measure out the baking soda line silicone baking mat in the large rectangle baking dish (with deep walls)
add sugar and water to the pot, use high-heat
the mixture reaches 284ºF (140ºC), stir in the honey
continue boiling until 320F ---- XiaoGaoJie: When sugar syrup temperature reaches 320°F/160°C, there is not much water left in the syrup. After it cools down, toffee stays dry and won't become sticky. Even without sealed in the plastic bag, it can stay fresh for a long time. ---- anna olson uses 300ºF (150ºC) is reached (the liquid will only be a pale amber colour, not caramelized fully).
Remove the pot from the heat and using a wooden spoon quickly sift in the baking soda mixture, stirring quickly and vigorously to make sure it has been incorporated Once the baking soda is no longer visible, stop stirring so as not to deflate the toffee.
Quickly scrape the frothing mass (it will keep growing and growing!) into the prepared pan and let it set (do not spread it) until cool – this can take up to 2 hours, and it will continue to grow a little more before it sets.