I made these yesterday for a party. Didn't really try to be too serious about it; more experimental than anything else. So I didn't do the "from scratch" version, but instead just used Nestle cookie dough for the bottom layer and Ghirardelli dark chocolate brownie mix for the top layer, with regular Oreos in between.
They actually came out as good as I could have imagined. Nothing was undercooked or overcooked, even though the cookie dough and brownie mix had different baking temperatures. Of course, edge brownies were still more chewy than the middle ones, but not by a signficant amount, surprisingly. I guess I just oiled up the pan well enough. Basically, everything came out as it should have; the cookie and brownie parts were cooked to perfection and the Oreo part was moistened into a well-integrated brownie-like texture.
My friends kept complimenting me on the brownies. One said they were the best he ever had. Hah.
I can't imagine how godly these things would be when made from scratch.
What I'm truly curious about is how well the other Oreo creme flavors (e.g. strawberry, mint, and peanut butter) work. And what about Double Stuf; is it overkill? Golden Oreos?
Lots of possibilities. I enjoy it when you can mix components together to come up with enhanced versions of classic desserts.