The cake was from the wedding of the Duke of Windsor (formerly Edward VIII) and Wallis Simpson and it really was sold at auction. The buyer paid $28,600 and said, “This is a memorabilia sale and so it is according to the importance of the person and the event and this was the most important event in the life of the Duke and Duchess of Windsor.” However, I don’t know if there are collectors who specialize in pastries, although I doubt it.
In general, I found that a lot of the plot points from Seinfeld were based on factual events, albeit loosely.
Like cheese, fruit cake is capable of lasting pretty much indefinitely under the right conditions - every now and again, the ‘light’ story at the end of the news is about some ancient bit of cake or cheese going up for auction. So it’s not completely implausible.
Is there somewhere you can find the recipes for the cakes, sweets, etc., served in historic times? i would like to eat some of the pastries that were served to Louis XIV-doe these recipes 9in modern form) exist somewhere?
I’d try The Cook and Housekeeper’s Complete and Universal Dictionary by Mary Eaton. The recipes are not quite what we’re used to these days – more general descriptions of ingredients, less precise quantities – but it has a lot of interesting things in it.
I proofread parts of it for PGDP awhile ago, so it might be available on Project Gutenberg by now.