Copycat Costco Chicken Alfredo Bake Recipe – Creamy, Comforting, and Crowd-Friendly

If you’ve ever grabbed the Chicken Alfredo Bake from Costco and wished you could make it at home, this recipe is for you. It’s rich, creamy, and packed with tender chicken and cheesy goodness. The best part?

You can prep it ahead, bake it when you’re ready, and feed a crowd without breaking a sweat. This version keeps the familiar flavors you love, with a few simple tweaks for even better texture and flavor. It’s weeknight-friendly, party-ready, and always a hit at the table.

Why This Recipe Works

This bake leans on a classic, silky Alfredo sauce made with butter, garlic, cream, and Parmesan—simple ingredients that deliver big flavor.

Using rotisserie chicken keeps things fast while adding a savory, roasted note. Par-cooking the pasta ensures it finishes perfectly in the oven without turning mushy. A blend of Parmesan and mozzarella adds both sharp flavor and melty pull.

And a quick broil at the end gives you that golden, bubbly top you expect from a good casserole.

Shopping List

• Rotisserie chicken (about 4 cups shredded; skin removed)
• Penne or rigatoni (1 pound)
• Unsalted butter (6 tablespoons)
• Garlic (4–5 cloves, minced)
• Heavy cream (2 cups)
• Whole milk (1 cup)
• Chicken broth (1/2 cup)
• Parmesan cheese, finely grated (1 1/2 cups, plus more for topping)
• Mozzarella cheese, shredded (2 cups)
• Cream cheese (4 ounces, softened)
• Olive oil (1 tablespoon)
• Italian seasoning (1 teaspoon)
• Crushed red pepper flakes (optional, 1/4 teaspoon)
• Fresh parsley, chopped (2–3 tablespoons)
• Kosher salt and black pepper

Instructions

1. Boil the pasta. Bring a large pot of salted water to a boil. Cook penne until 2 minutes shy of al dente (it will finish in the oven). Drain and toss with 1 tablespoon olive oil to prevent sticking.
2. Prep the chicken. Shred the rotisserie chicken into bite-size pieces, discarding skin and bones.You should have about 4 cups. Season lightly with salt, pepper, and Italian seasoning.
3. Make the Alfredo base. In a large saucepan, melt 6 tablespoons butter over medium heat. Add minced garlic and cook 30–60 seconds until fragrant, not browned.
4. Build the sauce. Pour in heavy cream, whole milk, and chicken broth.Bring to a gentle simmer and cook 3–4 minutes, stirring often.
5. Add the cheeses. Reduce heat to low. Whisk in cream cheese until smooth. Slowly add 1 1/2 cups grated Parmesan, stirring until fully melted and thickened.Season with 1 teaspoon kosher salt, 1/2 teaspoon black pepper, and red pepper flakes if using.
6. Combine. In a large mixing bowl, toss the cooked pasta, shredded chicken, and half of the mozzarella with the warm Alfredo sauce. Stir in half the parsley.
7. Assemble. Transfer mixture to a greased 9×13-inch baking dish (or two smaller dishes). Top with remaining mozzarella and a generous sprinkle of Parmesan.
8. Bake. Cover loosely with foil and bake at 375°F (190°C) for 20 minutes. Remove foil and bake another 10–15 minutes until bubbly and lightly golden. For extra color, broil 1–2 minutes, watching closely.
9. Rest and serve. Let the bake rest 5–10 minutes to set. Garnish with remaining parsley and serve warm.

Keeping It Fresh

For meal prep, assemble the casserole up to a day ahead, cover tightly, and refrigerate.

When ready to bake from cold, add about 10 extra minutes. To freeze, wrap the unbaked dish tightly in plastic, then foil, and freeze for up to 2 months. Bake from frozen at 350°F (175°C) for 60–75 minutes, uncovering for the last 15 minutes.

Leftovers keep in the fridge for 3–4 days.

Reheat gently in a 300°F (150°C) oven, covered, until warmed through. If it looks dry, splash with a little milk or broth before reheating to revive the sauce.

Health Benefits

• Protein-rich: The chicken provides a solid dose of protein to keep you full and support muscle maintenance.
• Calcium boost: Parmesan and mozzarella contribute calcium for bone health.
• Customizable veggies: Add steamed broccoli, peas, spinach, or roasted mushrooms to increase fiber, vitamins, and minerals without losing the comfort factor.
• Balanced portions: Pair with a crisp salad or roasted vegetables to round out the meal and keep portions satisfying but reasonable.

Pitfalls to Watch Out For

• Overcooking the pasta: If it’s fully cooked before baking, it may turn mushy. Stop a bit early.
• Curdled sauce: High heat can cause dairy to separate. Keep the sauce at a gentle simmer and add cheeses over low heat.
• Watery casserole: Don’t rinse the pasta, and avoid extra watery add-ins. Pat cooked veggies dry before mixing in.
• Under-seasoning: Alfredo sauce needs salt to pop, especially with milk diluting the cream. Taste and adjust before assembling.
• Dry leftovers: Add a splash of milk or broth when reheating to keep it creamy.

Alternatives

• Lighter version: Swap half the cream for evaporated milk, and use part-skim mozzarella.You can also reduce cheese by 25% and bump up veggies like broccoli or spinach.
• Gluten-free: Use gluten-free penne and ensure your broth and cream cheese are gluten-free. Bake as directed.
• High-protein twist: Mix in cottage cheese (blended smooth) or Greek yogurt after the sauce cools slightly. Fold gently to prevent curdling.
• Flavor boosters: Add sautéed onions and mushrooms, sun-dried tomatoes, or a squeeze of lemon to brighten the richness.
• Different proteins: Try shredded turkey, grilled shrimp, or crispy bacon crumbles for a change-up.
• Spice it up: Stir in a teaspoon of Cajun seasoning or a spoonful of Calabrian chili paste for heat.

FAQ

Can I use jarred Alfredo sauce instead of homemade?

Yes.

You’ll need about 3 to 4 cups. Warm it gently, then mix with chicken and pasta. Still add some freshly grated Parmesan to boost flavor and body.

What pasta shape works best?

Penne and rigatoni are ideal because they hold sauce and bake evenly.

Ziti or medium shells also work. Avoid very small shapes that overcook quickly.

How do I prevent the cheese from becoming greasy?

Use low, steady heat when melting cheeses and avoid pre-shredded cheese with lots of anti-caking agents. Finely grate Parmesan yourself for the best melt and flavor.

Can I add vegetables without making it watery?

Absolutely.

Steam or roast veggies first, then pat dry and fold in. Broccoli florets, peas, spinach, and mushrooms are reliable options.

What’s the best way to reheat single portions?

Microwave at 50–60% power in short bursts, stirring once and adding a splash of milk if needed. Alternatively, reheat in a small oven-safe dish at 300°F covered with foil.

Is cream cheese necessary?

No, but it helps stabilize the sauce and adds extra creaminess.

If you skip it, simmer the cream a touch longer and add a bit more Parmesan.

Can I assemble this the night before?

Yes. Cover tightly and refrigerate. Add a few extra minutes to the baking time since you’re starting from cold.

Final Thoughts

This Copycat Costco Chicken Alfredo Bake delivers everything you love about the original—creamy sauce, tender chicken, and gooey cheese—while giving you control over ingredients and add-ins.

It’s easy to scale, perfect for make-ahead nights, and flexible enough for healthier tweaks. Keep a pan in the freezer, and you’ll always have a satisfying, comforting dinner ready to go.