Put the cookies in the bowl of a processor and process until completely smooth. You'll need a full sized machine for this job, the small bowl won't fit all the cookies and nuts. In my machine this took a full 5 minutes. Pulse the machine and scrape down the sides if necessary. It will be dry and grainy for the first couple of minutes, then it will become a giant ball of stiff dough. Keep it going until the dough breaks down, and starts to loosen up. Eventually you will get a smooth buttery texture. When in doubt, keep processing. 5 minutes should be enough.
Add in the peanuts, and repeat the process for another 5 minutes. The butter is done when you have a sooth, creamy thick consistency. When in doubt, keep processing.
Pour the cookie/nut butter into a jar with a tight fitting lid and store at room temperature.
https://theviewfromgreatisland.com/cookies-and-cream-peanut-butter/ May 25, 2013