A couple nights ago, I built the elusive sextuple-stuf Oreo. That's where you start with three Double Stufs, take one cookie side off each of them, stick two of them together (known as a quadruple-stuf), carefully try to get one of the cookie sides off that and then, if successful, stick the last of the three Double Stufs on it.
Someday, I will try for the nigh-impossible octuple-stuf.