I have seen "noodles" used as plural a lot more often than it used as singular.
I found 155 examples of "noodles" on COCA but only 18 of "noodle".
On the other hand, "spaghetti " is almost always used as singular.
Both noodles and spaghetti are made of flour.
I don't think they can be counted like an apple or a pen.
They look similar, but why are they grammatically treated differently ?