What's the plural form of feuilletine? Here's the word you're looking for.
Answer
The noun feuilletine can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be feuilletine.
However, in more specific contexts, the plural form can also be feuilletines e.g. in reference to various types of feuilletines
or a collection of feuilletines.