What is the origin of the idiom "be like taking candy from a baby" and when to use it?

The idiom "be like taking candy from a baby" is used to describe a task or action that is exceptionally easy or effortless. It highlights that the activity or situation is so simple that it's comparable to taking something from a child who cannot resist or defend it. The exact origin of this expression is not precisely documented, but it has been used for many years in English.