I just made sunflower seed cheddar crackers. The dough is spread all over a layer of parchment on a cookie sheet . I baked for the required time but the parchment is stuck to the bottom of the crackers. They are not fully cooled, will that make a difference?
You might try brushing water over the back of the parchment paper, letting it sit for a while, and seeing if it will peel off better when damp.
Sometimes that will help release the sticking (although sometimes it won't), and other times it might soften the surface of your crackers enough to lose just the outermost layer to the process of getting the paper off. You might want to re-toast your crackers after, since the moisture won't help their storage.
If your crackers aren't cool when you're checking the sticking, it is better to let them finish cooling, sometimes that helps. I would suggest flipping the paper over and letting cool paper side up, to prevent moisture from accumulating where the cracker sits on the paper - the moisture itself may help, but letting moisten and dry out again may make the sticking worse.
In the future, you might want a thin layer of oil, or flour, to prevent the dough sticking to the paper while it bakes.