Store leftovers in an airtight container in the refrigerator for 3-4 days; can freeze for up to a month. When preparing the cheese mixture, letting all cheese reach room temperature first will ensure it melts evenly. For best pasta texture, boil until just al dente to avoid a mushy result when baking. If browning occurs, covering the dish with foil during baking can help protect the top without compromising cooking. Reheat leftovers in the oven at 350 degrees F until heated through. Serve with a green salad and Italian dressing. Pair with garlic bread for a hearty meal. Add roasted vegetables for a balanced plate. Make a meatless version with marinara and cheese. Replace spaghetti with spaghetti squash for a lighter dish. Add vegetables like spinach or bell peppers to the layers.