The word caramelle always refers to more than one sweet, but it can be confusing because this is something an English speaker would translate as either "candy" (mass noun) or "candies" (countable). The concept is simpler in Italian:
- do you like candy? ti piacciono le caramelle?
- do you like (the piece of candy/the candy/the sweet)? ti piace la caramella?
- this is my favorite (piece of candy/sweet/candy). questa è la mia caramella preferita.
- these are my favorite candies. queste sono le mie caramelle preferite.
Hope this makes sense :)