I don't know if this is right, but google reverse images says Mimusops elengi - Spanish Cherry. The part that connects the fruit to the branch doesn't look right for my ID
after some more extensive looking, this is the absolute closest I could find: Aglaia korthalsii https://live.staticflickr.com/7531/15631365749_da5a785c76_b.jpg (basing off second picture, description of fruit shape and flavor)
Thanks for the reply. It does look similar but there are significant differences, including size, flesh appearance, and the visible sepals on mimusops elengii, and the woody part of the stem readily pulls from the fruit stem, unlike how it appears in the Aglaia picture.
Here is a picture of the cleaned seed. I had to scrape off a lot of the brown seed coat, but the seed does have a line going lengthwise along it.

Tasting it again this morning, I am reminded of langsat and a little bit of wampee, which was my first guess, but I don't know much about wampee at all.