Translation:The girl does not have a cheese pie, she has a chocolate pie.
They're talking about a cheese pie and a chocolate pie, not 2 plain pies of which one has slices of cheese on it and the other chocolate smeared on top. So while cu can mean with, you have to look at context to see that they're referring to a type of pie, not a pie with a condiment on top.
For those having trouble with the long sentences, I have a tip that may work for you. What I do is I look for the comma and treat the part before the comma as a separate sentence than the part after the comma. The sentences may be related, but they are now separate so it makes it more manageable for me. This way I'm dealing with two (or more) smaller sentences and not one large one.
It is the sound of an "a" which does'nt (obviously) exist in English, -need to hear it to get it- it's sort of like a person with braces making a sound of an "a" from within their chest - mouth slightly ajar and making an "a" sound which is throaty yet wisperish.
An "a" which is "airy".