Which is correct? 1. What we want is additional resources. 2. What we want are additional resources.

This is a tricky sentence since grammatically both the sentences appear to be correct. But here we have to look for appropriacy, and from that point of view 'What we want is addition resources' is correct, as in this case 'additional resources' is treated as one item [in the probable list] and therefore singular. 

To answer the question we need to break down the phrase: "what we want," which means: the "thing" that we want; or the "thing", which we want.

It is clear that we are speaking about a singular noun "thing". Thus, the correct sentence is: what we want is additional resources.  

According to bbclearningenglish.com, which is a good reference, the correct sentence is "what we want is additional resources". The verb should agree with the subject, not the object.

Likewise, a sentence like "His biggest problem is his inaccuracies" is correct.check the resource here;

http://www.bbc.co.uk/worldservice/learningenglish/radio/specials/_aae/page.shtml

The correct answer is:  "What we want (is)...  because (is) here refers to the thing that we want to do...

so we are referring to a singular not plural

What we want IS  - this is correct 

You  can say like this:

What we want is an additional resource?    or

What we want are additional resources?

the correct answer is the first one.........................

The first one is the answer as already explained earlier. thank you

The second answer correct. 

I agree with the rest answers

What we want is additional resources.