What can I do with soft biscuits due to air exposure I had bought a biscuit packet and after eating some I left the packet in a poly bag with a knot.
However may be due to loosening of the knot, and hence, the air exposure, the biscuits have lost their crunchiness and have become soft.
It's now difficult to eat them!
If anyone can suggest any recipe so that they don't get wasted or if I can make them hard again!
My biscuits are normal sweet cookies with sugar crystals on their surface.
I have around 10-12 pieces left.
You can normally refresh them in the oven.  anywhere between about 150°C (for 6-8 minutes) and 190°C (3-4 minutes) should work, ideally taking them out just before they start to brown any more though of course that's a matter of guesswork
Leave to cool on a wire rack, and put in an airtight container as soon as they're cool.
In future, either put the twisted packet in a closed container, or clip it closed, though it may just be that you tried to store them for too long in high humidity.