The sponge-like structure is formed while the sugar is liquid, then the toffee sets hard.
The candy goes by a variety of names and regional variants, including honeycomb, sponge toffee or hokey pokey.
It’s quite messy to make and you really have to be quick with it or it solidifies so quickly that you can’t get it out of the pan, so be prepared to work quickly.
It’s easy to make, though you might find some trouble in cleaning your pan afterwards, but soaking in water and washing up liquid should sort the problem out.
Make sure you grease the cooking pan for your cinder toffee very very well, or it will stick like glue and you might need to cut it out.
To make the recipe extra indulgent, melt some chocolate and dip the cooled honeycomb in it.
Then leave to dry on a rack and you have your own homemade crunchie bar.
Once made, it is recommended to store your finished cinder toffee in a metal container at room temperature.
Sugar has a tendency to ‘sweat’ when stored in plastic and this could make your cinder toffee go sticky.