When a casserole is bubbling around the edges, the center can still be loose and cooler than you expect. That’s why I don’t judge this creamy chicken Alfredo broccoli bake by its edges alone; the middle gets its own check before the dish comes out of the oven. The result is a full pan of tender penne, cooked chicken, and broccoli tucked into a creamy Parmesan sauce, with mozzarella melted over the top.
The pasta gets a head start in boiling water, but it doesn’t cook all the way to al dente before it goes into the oven. That small bit of undercooking gives the penne room to finish in the Alfredo sauce instead of turning soft while the casserole bakes. I keep the broccoli florets small, too, so they’re ready at the same time as the pasta. Each forkful comes out creamy, with a little bite from the penne and a stretchy layer of cheese on top.
Kitchen Note
The Alfredo sauce should still pour easily before it goes over the pasta. Don’t simmer it until thick in the saucepan; it gets more body from the Parmesan and the time in the oven.
Save this Creamy Chicken Alfredo Broccoli Bake for a bubbling, creamy casserole with tender penne and a melted mozzarella top.
Why This Bake Starts With Pasta That Isn’t Quite Al Dente
A casserole keeps cooking after it leaves the stove. Penne that’s already fully tender before it goes into the dish has another 25 to 30 minutes in the oven, surrounded by hot sauce. By the time the center is ready, that pasta can be softer than you want. Cooking it two minutes short of the package’s al dente time gives it some room to finish without losing its bite.
That timing also helps the pasta take on the Alfredo sauce without becoming waterlogged. The drained penne and broccoli go into the oven coated in sauce, and the pasta continues to soften as the casserole heats through. If you start with pasta that’s too soft, there’s no way to firm it back up in the baking dish. Keep an eye on the package timing, and get the broccoli into the pot only for the pasta’s final two minutes. Then drain everything well before mixing it with the chicken and sauce.
Why This Bake Needs Both Heavy Cream and Whole Milk
- Heavy cream and whole milk — The cream brings richness while the milk loosens the sauce enough to coat the penne. Both matter here: using only milk makes a thinner sauce, while using only cream can leave the finished bake heavier. Whole milk is a good fit; skim milk won’t give the same body.
- Finely grated Parmesan — Fine shreds melt into the warm dairy more readily than coarse pieces. A block of Parmesan grated just before cooking is a reliable choice; pre-grated cheese is convenient, but it may not melt quite as smoothly.
- Shredded mozzarella — This is the top layer, so it gives the casserole its stretchy, browned finish. Freshly shredded mozzarella melts well, but packaged shredded mozzarella is a practical choice when you want to keep prep simple.
- Penne and small broccoli florets — Penne’s hollow center catches sauce, and small florets cook through during the short time they share the pot with the pasta. Cut larger broccoli pieces down so they don’t stay noticeably firmer than the penne.
- Cooked shredded chicken — Shredded chicken distributes through the casserole more evenly than large chunks, so there’s chicken in plenty of bites. Use chicken that’s already cooked and pull it into pieces small enough to mix through the pasta.
How to Keep the Pasta Tender Instead of Mushy in the Oven
Set Up the Dish and Cook the Pasta
Heat the oven to 350°F and brush a 9×13-inch baking dish with olive oil. Bring the water to a boil in a 6-quart pot, stir in the kosher salt and penne, and use the package’s al dente time as your guide. Add the small broccoli florets for the final two minutes of cooking, then drain the pasta and broccoli well. Don’t leave the drained pasta sitting in hot water; it keeps cooking there.
Warm the Cream Without Boiling It Hard
Melt the butter in a 3-quart saucepan over medium heat, then stir in the minced garlic for 30 seconds, until fragrant. Add the heavy cream, whole milk, black pepper, and nutmeg. Heat over medium for 4 to 5 minutes, watching for steam and gentle bubbles around the edges rather than a rolling boil. Take the pan off the heat before whisking in the Parmesan; the sauce should look smooth once the cheese has melted.
Coat the Pasta Before It Goes Into the Dish
Combine the drained pasta and broccoli with the cooked shredded chicken in a large bowl, then pour in the Alfredo sauce. Fold until the pasta and chicken are coated and the broccoli is distributed through the mixture. Transfer it to the oiled baking dish and spread it into an even layer. An even layer helps the casserole heat consistently instead of leaving a deep, slow-warming mound in the middle.
Bake Until the Center Is Hot, Then Let It Set
Sprinkle the mozzarella evenly across the top and bake for 25 to 30 minutes. Look for bubbling sauce at the edges, then check the center with an instant-read thermometer; it should reach 165°F before you take the dish out. A browned top alone doesn’t tell you whether the middle is hot. Rest the casserole for 10 minutes before serving so the sauce settles around the pasta.
Swaps That Keep This Alfredo Bake Creamy
Make It With Gluten-Free Penne
Replace the regular penne with an equal amount of gluten-free penne and follow its package timing, stopping about two minutes before al dente. Add the broccoli for the final two minutes as usual. Gluten-free pasta can soften more during baking, so check it at the early end of the bake time.
Use Rotini Instead of Penne
Rotini is another short pasta that holds the creamy sauce well. Use the same amount and cook it two minutes less than its package’s al dente time, adding the broccoli during the final two minutes. Its spirals catch sauce nicely, though the casserole will have a different bite from penne.
Leave Out the Chicken
For a chicken-free version, omit the cooked shredded chicken and keep the rest of the ingredients and method the same. The pasta, broccoli, and Alfredo sauce still make a satisfying baked dish, though it won’t be as substantial as the chicken version.
Storage and Reheating
- Refrigerator: Cover leftovers and refrigerate for 3 to 4 days. The pasta softens as it sits, and the sauce thickens.
- Freezer: Freeze portions in airtight containers for up to 2 to 3 months. The cream sauce may separate a little after thawing, but stirring during reheating helps bring it back together.
- Reheating: Warm individual portions in the microwave in short bursts, stirring between bursts; add a small splash of whole milk if the sauce looks tight. Avoid heating one portion for a long stretch without stirring, since the edges can get hot before the center.
Questions That Come Up While Making This Chicken Alfredo Bake
Creamy Chicken Alfredo Broccoli Bake
Ingredients
Equipment
Method
- Heat the oven to 350°F and brush a 9x13-inch baking dish with the olive oil.
- Bring the 4 quarts of water to a boil in a 6-quart pot.
- Stir in the kosher salt and penne, and cook 2 minutes less than the package’s al dente time.
- Add the broccoli for the final 2 minutes, then drain well.
- Melt the unsalted butter in a 3-quart saucepan over medium heat, add the minced garlic, and cook for 30 seconds, stirring, until fragrant.
- Stir in the heavy cream, whole milk, black pepper, and ground nutmeg, and heat over medium until steaming with gentle bubbles around the edges, 4 to 5 minutes.
- Remove the saucepan from the heat and whisk in the finely grated Parmesan cheese until melted and smooth.
- Combine the drained pasta and broccoli, cooked shredded chicken, and Alfredo sauce in a large bowl, then transfer the mixture to the prepared baking dish.
- Sprinkle the shredded mozzarella cheese evenly over the top and bake for 25 to 30 minutes, until bubbling at the edges and the center reaches 165°F on an instant-read thermometer.
- Rest the bake for 10 minutes before serving.