PREHEAT oven to 350° F. Grease two 8 x 4-inch loaf dishes.
COMBINE ricotta cheese, spinach, eggs and milk in medium bowl. Place one-fourth pasta in each prepared dish. Add one-fourth sauce and half ricotta mixture to each dish. Top each with half remaining pasta and half remaining sauce. Sprinkle both dishes with Parmesan cheese. Cover one dish with plastic wrap, then overwrap with foil. Label and freeze for up to 2 months.
COVER remaining dish with foil. Bake for 40 to 45 minutes or until heated through. Let stand for 10 minutes before serving.
TO BAKE FROZEN LASAGNA: Place dish in refrigerator overnight. Preheat oven to 375° F. Remove foil and plastic wrap; recover with foil. Bake for 1 hour or until heated through. Let stand for 10 minutes before serving.
