Grease and line a loaf tin with non-stick baking paper.
In a medium pot, over low heat, combine the water, sugar and golden syrup until completely dissolved. Turn the heat up and simmer until the syrup boils and turns into a dark amber colour. If using a thermometer, it should reach 150°C.
Remove from the heat and add the bicarbonate of soda. Whisk until the honeycomb foams up then immediately pour it into the prepared baking tin. Allow to cool for about 1 hour and 30 minutes.
Repeat the process to get another bar of honeycomb.
Once the honeycomb is completely cold, remove from tins and stack the two loaves. Melt the chocolate and spread to make an even layer. When the chocolate is solid, turn upside down and cover the rest of the bar with chocolate.
Let cool, and enjoy!