Two Oreo cookies. A whole buncha peanut butter. Brownie mix. Sandwiched, layered, gooped. Muffin pan. Oven for 25 or so.
My thoughts post-operation: Might have been better with soft Oreos, so if you live in the States and have access, go for it. Next time I might dip the Oreos and milk to soften for the re-baking. A bit too hard this way. Also, I’m not sure what I did wrong, but the brownie mix stuck to the paper cups so the bottom layer didn’t work out.
Bottom line: Do it.