In short, imagine a taffy made out of malt syrup.
But the beauty is that using different starch(adjunct) gives different flavours.
Please note that getting this 'right' is a very difficult and artisan thing. Especially when it comes to forming the air channels inside.
Use 1 part malt and 1 part starch source, my No.1 favourite is pumpkin.
Rice gives somewhat bland taste.
Mash, then filter, then simmer it (NOT boil) for long long time, this will take hours so be prepared to spend entire day doing this.
(Note, more traditionally, it was done by a process similar to decoction)
Now, how the bubble forms during the simmering process will determine how soft it is.
If the bubble forms like,
1) small frequent bubbles, VERY soft
2) large regular bubbles, somewhat soft
3) Lava-like bubbles, very chewy
Remember, it's entirely upto you, but most go for 2 or 3.
When it's all done, have a tray ready with baking paper, then pour the
'syrup' into it and cool it.
When you leave a dent with a finger (on the 'syrup'), if the 'syrup' feels springy/ bouncy, Take the whole block out, stretch it, fold it, stretch it, fold it again and again and again, about 100 times. During this process, the mixture will become lighter in colour.
Then put into cylinderical shape about half inch thick, but how you shape it easy entirely upto you.
Once its all done, you can put bean/peanut powder on it for flavour and preventing it from sticking to each other.