piece of cake
Definition from Wiktionary, the free dictionary
Attested since 1936, originally in American English. The notion of facility probably derives from many cakes having agreeable tastes, and hence ‘easy’ to consume.
- Used other than as an idiom: see piece, cake.
- (idiomatic) A job, task or other activity that is pleasant – or, by extension, easy or simple.
- Sure, no problem. It'll be a piece of cake.
- (an activity that is easy): breeze, cakewalk, child's play, cinch, doddle, duck soup, walk in the park, walkover
- See also Wikisaurus:easy thing
simple or easy job