To freeze: Line 13x9-inch (3-quart) glass baking dish with plastic wrap, leaving enough overhang to completely enclose assembled manicotti. Cool sauce completely, covered, 30 to 40 minutes in refrigerator before assembling manicotti. Assemble manicotti in dish, and cover with another layer of plastic wrap. Freeze unbaked manicotti about 8 hours or until completely frozen. Transfer frozen manicotti to labeled 2-gallon resealable freezer plastic bag. Remove air; seal and freeze up to three months. To bake: Remove plastic wrap; transfer to 13x9-inch (3-quart) glass baking dish sprayed with cooking spray. Cover tightly with foil; thaw completely in refrigerator, up to 48 hours. Heat oven to 375°F. Bake 48 to 55 minutes or until sauce is bubbling; remove foil, and bake 12 to 15 minutes or until bubbly (165°F in center). Let stand 5 to 10 minutes before cutting and serving.