What is Scraper Bread?
1.
Toast that has been heated too long and has burned, however, can be made edible (tolerable) by removing the top layer with a knife (in a scraping motion) leaving the burnt toast-filings behind to throw away.
Typically this is only performed when no more bread is available/one is too poor to waste burnt toast.
"we had grilled cheese for dinner, but we had them on scraper bread because I left the toast in the toaster too long.
See