Don't be fooled by the outside appearance. The first time I went there I didn't even think it was a bakery. It doesn't look like much, but it has the best chocolate chip cookies anywhere.
The cookies are huge - probably the size of 3 regular cookies. Have a bit of a peanut butter cookie taste to them, but it's subtle.
They aren't cheap (I think they're $18/dozen) but worth every penny! A box of a dozen must weigh 5 pounds. You'll be surprised when you pick up the box. One of the "must try" foods in Pittsburgh!