Choose the correct collective noun for the phrase given below.
A ____ of cookies.

A collective noun is a collection of things taken as a whole. It refers to a group of things, people, or animals. 

Below are some sentences using collective nouns in bold.

A flock of birds flew overhead.
They prepared the fleet of ships for the voyage.
She brought a pile of cookies out to the family room for the kids.
He taught a small class of 12 students.
They rescued a litter of kittens from the alley.

 

Source: Britannica