Creamy Chicken Alfredo Casserole

My neighbor brought this over one Tuesday when I had the flu, and I swear it tasted better than anything I'd made myself in months. The steam rising from that casserole dish smelled like comfort and garlic, and I was hooked before the first bite. She told me it was her weeknight secret, the thing she made when everyone was cranky and dinner needed to just work. I asked for the recipe the next day, and it's been in my rotation ever since.

I made this for my son's birthday dinner last year because he asked for something cozy instead of fancy. He invited three friends over, and they demolished the entire pan before I could even sit down. Watching them scrape the dish clean while laughing about something from school made me realize this recipe isn't just food, it's the backdrop to good nights. I've made it a dozen times since, and it never gets old.

Ingredients

• Penne or ziti pasta: These shapes hold the sauce in every ridge and hollow, making each bite creamy and satisfying without feeling too heavy.
• Cooked chicken breast: Rotisserie chicken is my favorite shortcut here, it's already seasoned and saves you 20 minutes of prep time.
• Unsalted butter: This forms the base of the sauce and lets you control the saltiness, which matters when Parmesan is involved.
• Garlic: Fresh cloves make all the difference, the smell when they hit the butter is half the magic of this dish.
• Heavy cream: The sauce needs this richness to coat the pasta and stay silky even after baking.
• Parmesan cheese: Freshly grated melts smoothly and tastes sharper than the pre-shredded kind, which can turn grainy.
• Salt, black pepper, and nutmeg: The nutmeg is optional but adds a warmth that people notice without knowing why.
• Mozzarella cheese: This creates that golden, bubbling top layer everyone fights over.
• Fresh parsley: A handful at the end brightens the whole dish and makes it look like you really tried.

Instructions

Preheat and Prep:

Set your oven to 375°F and grease a 9x13-inch baking dish so nothing sticks. This step is easy to forget, but it saves cleanup later.

Cook the Pasta:

Boil the pasta in salted water until it's just shy of tender, it will finish cooking in the oven. Drain it well so the sauce doesn't get watery.

Start the Sauce:

Melt butter in a large saucepan over medium heat, then add the garlic and let it sizzle for about a minute. The kitchen will smell incredible, and you'll know it's ready when the garlic turns fragrant but not brown.

Build the Alfredo:

Pour in the heavy cream and bring it to a gentle simmer, then stir in the Parmesan, salt, pepper, and nutmeg until the sauce is smooth and glossy. This takes patience, but rushing it can make the cheese clump.

Combine Everything:

Toss the cooked chicken and drained pasta into the sauce, stirring until every piece is coated. The pasta should look creamy and luxurious.

Assemble the Casserole:

Pour the mixture into your prepared baking dish and spread it evenly, then sprinkle the mozzarella on top in an even layer. Don't skimp on the cheese, it's the best part.

Bake Until Golden:

Slide the dish into the oven and bake for 25 to 30 minutes, until the cheese is bubbling and turning golden brown in spots. The edges will crisp up a little, which is perfect.

Rest and Serve:

Let the casserole sit for 5 minutes before serving so the sauce can thicken slightly. Sprinkle fresh parsley over the top if you have it, and dig in.

Save to Pinterest

One night I added steamed broccoli because I felt guilty about the lack of vegetables, and my daughter actually asked for seconds. It turned into our Sunday night tradition, and now she helps me grate the cheese while we talk about her week. This casserole has become less about the recipe and more about the time we spend making it together.

Ways to Make It Your Own

I've stirred in sautéed mushrooms when I had them sitting in the fridge, and they added an earthy depth that my husband loved. Spinach works beautifully too, just wilt it in the sauce before adding the pasta. If you want a little kick, a pinch of red pepper flakes in the garlic step changes the whole mood without overpowering the creaminess.

What to Serve Alongside

A crisp green salad with lemon vinaigrette cuts through the richness and makes the meal feel balanced. Garlic bread is overkill but also completely worth it if you're feeding a crowd. I've poured a glass of Chardonnay with this more times than I can count, the buttery wine just fits.

Storage and Reheating

Leftovers keep in the fridge for up to three days, and they reheat surprisingly well in the microwave with a splash of milk to loosen the sauce. I've also frozen individual portions in airtight containers, and they thaw beautifully for those nights when cooking feels impossible. Just bake from frozen at 350°F for about 40 minutes, covered with foil until heated through.

• Cover leftovers tightly to keep the pasta from drying out in the fridge.
• Add a tablespoon of milk or cream when reheating to bring back the silky texture.
• Freeze in single servings so you always have a quick meal ready to go.

Save to Pinterest

This casserole has saved more weeknights than I can count, and it's never let me down. I hope it becomes one of those recipes you reach for when you need something warm, easy, and absolutely satisfying.

Recipe Questions & Answers

→ Can I make this casserole ahead of time?

Yes, you can assemble the casserole up to 24 hours in advance. Cover it with plastic wrap or aluminum foil and refrigerate. When ready to bake, add 5-10 minutes to the cooking time since it will be cold from the refrigerator.

→ What can I substitute for heavy cream?

You can use half-and-half for a lighter version, though the sauce will be less rich. Alternatively, mix 1 cup milk with 2 tablespoons cornstarch for a thicker consistency, or use evaporated milk for added richness without excess fat.

→ How do I prevent the pasta from becoming mushy?

Cook the pasta just until al dente, which means it still has a slight firmness when you bite it. Since it will continue cooking in the oven, undercooking it slightly here ensures the final texture is perfectly tender.

→ Can I add vegetables to this dish?

Absolutely. Steam broccoli, spinach, or sauté mushrooms separately, then fold them into the sauce mixture before adding it to the baking dish. This adds nutrition and complements the creamy Alfredo beautifully.

→ What's the best way to store and reheat leftovers?

Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat in a 350°F oven covered with foil for 15-20 minutes, or microwave individual portions with a splash of milk to restore creaminess.

→ Is this gluten-free?

Traditional penne contains gluten, but you can easily make this gluten-free by using gluten-free pasta. All other ingredients are naturally gluten-free, making substitution simple.