Shade Loving Fruit Trees

Hi all,
I have several acres of forested land (an early stage forest full of tulip trees and various invasive undergrowth).

I want to plant fruit tress within this forest, trees that will bear edible fruit in the shade. So far I have a lot of pawpaw and persimmon planted, growing, and starting to bear. I am planting some American plum right now, but I am planting it on the edge. What fruits can go deep in the shade?

What do you recommend?

Zone 6, central Pennsylvania, USA.

I'd say serviceberries. The Native tree species requires natural soil conditions, though, which means your woods have to be healthy enough to have its own, natural layer of topsoil under the leaf litter, a few inches deep, or you'd have to artificially recreate the proper conditions.

Deerberries might also be a good call & black raspberries like partial shade & a lot of moisture, though none of those are trees. I've also caught Chokecherries managing themselves as undergrowth shrubs & still producing a fair amount of fruit, so I think pincherries- more native to the Appalachian Mountains- would do the same, if you can find any. Maybe also elderberries.

Sour cherries grow in shade.  They are not native to Appalachia, though they should grow well there.

Gooseberries and currants are happy in the shade, particularly blackcurrants.