Help With A 1 Cent Franklin From The Philippines

I think the fantasy explanation can't be ruled out, and it's the most economical answer, but it has a flaw: it's based solely on the rarity of the stamp, without any solid red flag to draw on. Nor could it explain why the cancellation mark is above the violet one (or so it seems...).
On the other hand, the option of a shipment from the US to the Philippines during the Spanish administration, as Zebraman suggests, seems more consistent with the fact that the violet mark was approved by the postal authority that issued it and could be below it. It's also consistent with the use of an archaic Spanish term in an Anglo-Saxon context to refer to the Spanish administration. It's just a theory, because I don't really know what the shipping process to the Philippines from the US was like at that time, but it is known that stamps related to the Philippines ended up bearing the black overprint "Philippines". Another detail, not entirely conclusive, but the stamp doesn't appear in Philippines or US; it appears in Spain among old abandoned albums, mainly containing Spanish stamps from the 1930s to the 1970s…

Two points:

Which marking is above or below the other is unknown. Even if the violet marking was underneath, it still proves nothing.

More importantly, the potential "overprint" being discussed is the most poorly proportioned "overprint" you could imagine since, as Partime's retroreveal shows, it spans beyond the perimeters of the base stamp. No postal authority or ad-lib postal person would be so unthoughtful IMO.

And finally, there is the 2020 HR Harmer sale, The Julian Cabarrus Collection of the Philippines, which is a stunning and thorough collection of Philippines overprinted material. It has no such animal as the OP's stamp and if Mr. Cabarrus did not have it than it doesn't exist.

https://stampauctionnetwork.com/HA/HA3034.cfm

This is a s-t-r-e-t-c-h to say the least. Let's see if we can get ten more topic pages out of this.

Forget the over or under argument. It's impossible to tell without a super clear enlarged image, such as the VSC6000. And even then it might not be possible for sure. There is already enough information about it here to think it a total fantasy.