Easy as pie

I was writing an email to a client and I used the idiom "easy as pie". Although I know how to use it, I was never quite sure of its origin. I've seen my mom make pie and it's not easy at all. Now eating a pie, that's easy. Well, a slice of pie, cause eating a whole pie isn't easy too. It also has to be good pie, terrible tasting pie is hard to consume and might not go down well. So, to be clear, next time use -> Easy as eating a really good slice of pie.

But really, this link, makes this entry pure blabber :P