One. The double vowel indicates the length of the sound - this is something that a lot of people struggle with, especially if their language is more concerned with stress than sound length. But if you compare "ma" (not a word in Finnish except shorthand for "Monday") and "maa" you should hear a clear difference in how long the a sound is.
If you wanted to have a word like this pronounced in two syllables, you would spell it as something like "ma'a". You see this in some words like "vaa'an" (genitive form of vaaka, "scale"), since having three a's in a row is getting a bit hard to read. Here, the syllables are vaa-an instead of some super long vaaaaaaan.