How to say 'pasta' in Spanish: Pasta. It's the same spelling as it is in English. The only difference is the vowel sound; it's not an 'ah' sound, it's a 'aa' sound; both on the fist A and on the second A. Same sound, 'aa'. You try it. This is a more round vocalized A.
If you want to say something like 'I like my girlfriend's pasta', you would say, "Me gusta la pasta de mi novia." You try it. If I ask you '?Te gusta la pasta de tu novia?' you would say, "Si, me gusta la pasta de me novia." Try it. ?Te gusta la pasta de tu novia?
That's how to say 'pasta' in Spanish.