Apples, Peaches, Pumpkin Pie

Cas has no intention of letting Sam rot in the Cage, but even before the surviving members of Team Free Will leave Stull, Cas receives a plea from the future that sends him on a very different path from the one he'd planned to follow. Can he keep his promise and still help Dean keep his pledge to pursue the apple-pie life with Lisa and Ben? (AU from "Swan Song," S9 spoilers)