It would make more sense to me to say "ten pullas"
Why ten pulla? Maybe ten pullas or, better yet, ten buns.
Pulla should be translated as buns.
Buns has too many different meanings in different English speaking countries
The English plural of "pulla" is "pullas". It's currently accepted, but only because it sees it as a typo.
I tried to answer “Elsa would like to buy ten pulla” since that seems to me a more normal polite way of speaking
That's conditional, and in Finnish it would be haluaisi.