I'm made from milk but I'm not a drink, I age in the dark more than you think. With or without holes, I'm served with ease, Slice me up, who am I please?

I don't start with E and I don't end with E but I do have a letter. -this is a spin on a classic riddle that comes along every once in a while-

It's a bird! It's a plane! No wait, I can't really tell, Then I must be me, only three letters to spell

Close one eye? Not so fast! No need to wink with this spyglass. Gaze at stars. Read far off words. One common use is for the birds!