This is a perfect congruent conflation of “easy as pie” and “it’s a piece of cake”, both meaning a very easy task or accomplishment. Cakes and pies seem to be easily muddled in one’s mind, as can be seen in earlier posts containing pies and cakes (see, e.g, https://malaphors.com/2013/01/01/its-as-easy-as-falling-off-a-piece-of-cake/ and https://malaphors.com/2016/08/10/the-man-is-a-nut-cake/). “It’s a cakewalk” might also be in the mix, again meaning something easy. A tip of the hat to John Kooser for uttering this one and immediately sending it in! (malaphor rule #1 is write it down immediately after hearing or saying the malaphor as you will quickly forget it).
Mike Kovacs, Vice President of Malaphor Hunters (MAHU), heard this one at a meeting. It think it is a conflation of “simple or easy as pie” (very easy or simple) and “clear as mud” (not understandable). Maybe the speaker was thinking of his childhood, making mud pies? And of course mud and pie are both three letter words, worthy of a mix-up. Could the movie Blood Simple also have been on the speaker’s mind? Blood rhymes with mud. A big thanks to Mike for hearing this one and sending it in!
This is a mash up of “it’s as easy as falling off a log”, “easy as pie”, and “it’s a piece of cake”, all meaning something very easy. This is a great example of a congruent malaphor, when two or more root expressions have the same or similar meaning. These kinds of malaphors are almost always understood by the listener because the idioms express the same thought.