Favoritos de restor3

I've never seen a fruit on this tree before. I did a quick glance but couldn't find any others, nor any flowers. I'm not sure if I just never noticed it before or if it's not actually a fruit.
The observation is specifically for the fruit in case it's actually a gall. The rest of the tree is in there for context

Edit: changed this to cultivated because of the location of the plant's natural range. I'm going to assume that someone planted this tree here intentionally a long time ago, which is why no one was 100% sure about what the plant is
I guess it's possible that it could be a feral tree, but that seems unlikely to me