I'm learning lots of cake history from Kurtos dot EU! I've been focusing my efforts for now on two old recipes. This one is from 1582 and supposedly describes the first layered spitcake (i.e., the first tree cake). A second one (whose transcription/translation I haven't put online yet) is from 1769, containing the first "modern" baumkuchen recipe. I'm not sure what "modern" means in that context, but that's the description used by Fritz Hahn. Fritz Hahn, by the way, was a baumkuchen historian who did a ton of very useful research in the 1960s and cited his sources very well. Me discovering him is the reason why I've suddenly switched to paleography and historical fact-finding.