What is the collective noun for sweet?

There isn't a specific collective noun for "sweets" in the same way that you might have a "flock of birds" or a "herd of elephants."

However, you could use several terms depending on the context:

General terms:

* A collection of sweets

* A variety of sweets

* An assortment of sweets

* A box/bag/jar of sweets

* A selection of sweets

More specific terms:

* A jar of preserves (for jams and jellies)

* A tray of pastries

* A bowl of candy

Ultimately, the best collective noun for "sweets" depends on the specific type of sweet you're referring to and the situation.