Definition from Wiktionary, the free dictionary
Alternative forms 
- (childish) Really simple
- Now now Benny Wenny, don’t cry about it, learning how to add fractions is easy peasy!
Usage notes 
In informal contexts it is reasonably common to further extend this phrase with a nonsensical rhyme, probably due to its frequent use around young children. Common examples include:
- See also Wikisaurus:easy