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I would pick the biggest leaves off. They don't taste nearly as good and this will cause the plant to grow a bunch of new, tasty, smaller leaves. I don't know why it looks like that. Someone else will tell you, I'm sure.

Hello Matt. Several years ago I had the exact thing happen to my basil... my sister told me it looked like a kind of fungus. We were never really certain what it was but...

I bought a fungus/insecticide duo (mine was not organic) and sprayed the plant thoroughly. After roughly 3 weeks of spraying and pruning the plant was cured.

Btw, what part of VA? I just moved from Stafford.

Woodbridge, actually -- not too far from Stafford!

After reading purpleinopp's advice, I pinched off the larger leaves plus all those with the questionable spots. I suspect curing the problem won't be that easy, but we'll see. So far the plant doesn't seem to be suffering. If this doesn't do the job, I'll try a fungicide. Thanks for the advice.

*Not* fungus.

Heat stress and ran short of water.