In an English class 48 years ago, scarfs was the correct word. Today you can use scarfs or scarves. My preference is scarves. I think it is more natural - like life and lives.

As a native English speaker I tend to say "scarfs" if I'm talking fast or not worrying about being correct ,even though it is correct. When I say "scarves" I, personally say it when I'm trying to speak more correctly.

Both are correct ^^

as i learned, both of them are right.

I would say, and write, one scarf, two scarves.