Researching for a friend and cause I'm interested.
Some people know it as 'cracker pie' or soda cracker or Ritz cracker pie or mock apple pie. Some use whole eggs, some whipped whites only. Some call for chopped dates or pecans or (??) canned fruit cocktail. Some add 1-2 Tbs apple cider vinegar.
I've got recipes in White Trash Cooking I and II (both are wonderful books) and references in my 1995 facsimile edition of Mrs. Hill's Southern Practical Cookery and Receipt Book (pub. 1872). It's clearly an old way of pie filling, my guess is it was revived (if ever lost) in the 1930s/depression era to 'use what you have' at a hard time.
Anyone have any historical information? My brief search of blogs doesn't help much beyond contemporary posts about something writers have just recently re-discovered. Still looking though. All help much appreciated.