Try this:
http://baking.about.com/cs/brownies/a/withasecret.htm
This "secret" to this recipe's moistness is the corn syrup (that also
explains why the best packaged brownie mixes use those little liquid
"chocolate packets", which contain corn syrup. Although this recipe
doesn't mention it (and I have not tried it), substituting bread flour
for the all-purpose flour will make the brownies chewy (the high gluten
content does the trick).
Art