I can't understand why anyone still buys regular Oreos. Like, there might be a subset of people who think that creme-filling sucks, but I can't imagine these people would opt for regular Oreos over, say, E.L. Fudge or Malomars. And yet Oreos continue to sell, and sell way better than Double Stuf.
Anyone who has had both types of cookie knows it is no contest. So the only rationale I can think of for keeping regular Oreos around is so that they continue to act as a framing device for Double Stuf; without regular cookies, the double creme would not appear as big and special as it currently does. Everything is relative. If what we currently know as "Double Stuf" had instead been just "Oreos" at the time of the cookie's inception, it wouldn't be so glamorous.
Here's the solution:
1. Create Quad-Stuf. Shouldn't be hard, or confusing.
2. Get rid of the regular Oreo.
3. Rename Double Stuf as "Oreos" and Quad Stuf as "Double Stuf."
4. Profit.
5. Repeat steps 1-4 every 2 years until you hit a profit inflection point because all of your consumers have undergone coronaries.