Make your peanut butter based food: pie, cookie, sandwich. And, if warm, let it cool.
Flash freeze it by placing it in a single layer on a cookie sheet for a few hours.
Wrap it up in portions with sheets of plastic wrap. Make sure each portion is completely and securely wrapped.
Pop your wrapped portions into an airtight container or a freezer bag.
Seal it up by squeezing all the air out of the bag and zipping it closed. Or, by securing the lid on top of the container.
Label the package on the outside with the date and toss back into the freezer.