Yes, you can. Fill all the shells with the spinach and ricotta mixture. Place the filled shells on a large sheet pan. Tightly cover with plastic wrap and then foil and allow to freeze completely. Once frozen, transfer the shells to large freezer bags. Remove any air and return to the freezer. u003cstrongu003eYou can freeze these stuffed shells for up to 3 months.u003c/strongu003e