easy as pie = very easy

as easy as pie はとても簡単、お安い御用、朝飯前、、、そのような意味。5:59 is that really all there is to it? not quite, huh? turns out making pie is not necessarily easy as pie. パイを焼くのは決して楽じゃないことがわかった。

Pie Making Secrets From the Midwest - Food Tripping With Molly Season 3, Episode 5

https://www.youtube.com/watch?v=iGleYTUn5VI  4:06 it was easy as pie to post on BACKPAGE. エロサイトのバックページに自分の裸の写真を掲載するのはお茶の子さいさいだった？ 　
Girls Bought and Sold Online

https://www.youtube.com/watch?v=gXLdN3rM1ZU  1:40 when it's as easy as closing your eyes.
American Dream - Nitty Gritty Dirt Band

https://www.youtube.com/watch?v=kh-OmhPmaMQ  1:32 it's just as easy as locking it up.
Stolen bikes an increasing problem in Hillsborough County

https://www.youtube.com/watch?v=ppbDmYb5rFc  0:11 it's as easy as rolling on paint. 落書きを消すのはペンキを塗るだけのたやすい作業だ。
Volunteers grab a brush to combat graffiti

参考リンク
http://bridge-english.blogspot.jp/2012/08/blog-post_8861.html  お安い御用を英語でなんと言うか？
http://bridge-english.blogspot.jp/2011/06/piece-of-cake.html  Piece of Cake
http://bridge-english.blogspot.jp/2010/12/choroi-rakusyou.html  チョロいを英語でなんと言うか？

練習問題解答
a-4698 easy as pie