Meaning: something that can be easily accomplished.
Meaning: when something good is added to another good thing that you already have
Example: Everyone expected him to do well in the exams. Getting first rank was the icing on the cake. Read on
Meaning: be a great commercial success
Example: These books are selling like hotcakes. Read on
Meaning: very easy task
Example: Don't worry, Sophie - this job interview will be a piece of cake for you - you have all the skills they need and I think you're absolutely the best candidate. Read on