Can I make an apple pie today and leave it out on the counter for tomorrow?

Yes. Just don't leave it to cool on a windowsill where any passing cartoon character can snaffle it.


(let it cool completely before covering it in anything. Steam will destroy the crust)

I would recommend, though, taking precautions against a soggy pie crust if you're going to leave the pie sitting for several hours! You could drain the apples, then reduce their juices in a saucepan! You could also par-bake the crust: https://food52.com/blog/10858-everything-you-need-to-know-about-par-baking

As long as there's no custard in it or anything like that, I say go for it! The fridge tends to mess with the crust anyways.

Yes, I think if you're planning to eat it tomorrow, it should be fine to keep it on the counter, lightly covered with plastic wrap. Beyond that, I'd keep it in the fridge and then rewarm it in the oven before serving.