There’s just something about Southern casseroles that feels like a warm hug on a busy night. Whether you grew up with them or discovered them later in life, a good Southern casserole hits all the right notes—comforting, creamy, and packed with flavor. And let me tell you, this Irresistible Spicy Southern Chicken Spaghetti Casserole takes those cozy vibes and turns the flavor dial all the way up!

This dish combines everything you love about classic Southern cooking with a bold twist of heat. We’re talking tender shredded chicken, al dente spaghetti, and a cheesy, creamy sauce spiced just right with Cajun seasoning, smoked paprika, and a touch of cayenne. Plus, there’s the satisfying crunch of golden Parmesan on top once it’s baked to perfection. Whether you’re planning a weeknight dinner, feeding a hungry crowd, or bringing something special to a potluck, this recipe is a guaranteed crowd-pleaser.

Now, I’ll be honest—I grew up with casseroles like this making a regular appearance at church gatherings and family reunions. But adding a spicy twist? That came later when I started playing around with recipes in my own kitchen. I love how the flavors in this version wake up your taste buds without being overwhelming. It’s the kind of dish that makes people come back for seconds (and maybe even thirds).

Ready to get started? Let’s jump into the first steps of this flavor-packed casserole.

Ingredients You’ll Need

Here’s everything you need to pull together this hearty, comforting dish:

• 12 ounces spaghetti

• 2 tablespoons butter

• 1 small onion, diced

• 1 green bell pepper, diced

• 2 cloves garlic, minced

• 1 can (10 ounces) diced tomatoes with green chiles, drained

• 1 can (10.5 ounces) cream of chicken soup

• 1 cup sour cream

• 2 cups shredded cooked chicken

• 1½ cups shredded cheddar cheese

• 1 teaspoon Cajun seasoning

• ½ teaspoon smoked paprika

• ½ teaspoon black pepper

• ¼ teaspoon cayenne pepper

• Salt to taste

• ½ cup grated Parmesan cheese

• Chopped parsley for garnish (optional)

STEP 1: Cook Your Pasta

Start by bringing a large pot of salted water to a boil. Add your spaghetti and cook it just until al dente—this is key because it’s going to keep cooking a bit in the oven. Once the pasta is ready, drain it and set it aside.

Tip: Don’t overcook the spaghetti. Keeping it slightly firm ensures it won’t get mushy after baking.

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STEP 2: Sauté the Veggies

While your pasta is draining, go ahead and melt the butter in a large skillet over medium heat. Toss in your diced onion and green bell pepper. Let them cook for about 4 to 5 minutes, stirring occasionally, until they’re softened and fragrant.

Next, stir in the minced garlic. You only need about a minute here—just long enough to let the garlic release its aroma without burning.

Pro Tip: If you’re a fan of smoky heat, you can even add a pinch more smoked paprika here while the veggies are cooking.

STEP 3: Build the Creamy, Spicy Sauce

Now it’s time to bring all the creamy, savory goodness together. Into the skillet with your softened veggies, add:

• Drained diced tomatoes with green chiles

• Cream of chicken soup

• Sour cream

• Shredded cooked chicken

• Cajun seasoning

• Smoked paprika

• Black pepper

• Cayenne pepper

• A pinch of salt (to taste)

Give everything a good stir to make sure it’s fully combined and heated through. You’ll start to smell those spices coming to life, and it’s so good.

Now that your kitchen is filled with the smell of buttery onions, peppers, and a spicy Southern-style sauce, it’s time to bring everything together and bake this casserole to bubbly perfection. This next part is where the magic really happens—spaghetti gets tossed in all that rich flavor, cheddar cheese melts into the sauce, and the whole dish gets finished off with a golden, crispy Parmesan topping.

The best part? This recipe is super forgiving and customizable. Whether you’re using leftover rotisserie chicken or cooking fresh just for this, the results are always crave-worthy. Let’s get back to it!

STEP 4: Combine Pasta and Sauce

With your creamy, spicy sauce ready and your spaghetti cooked and drained, it’s time to bring it all together.

Add the spaghetti into the skillet with the sauce. Using tongs or a large spoon, gently toss the pasta until it’s completely coated in that luscious mixture. This part might take a minute or two—just be patient and make sure the spaghetti is evenly mixed through.

Now fold in the shredded cheddar cheese. It will start to melt right away, making everything even creamier and extra cheesy.

Tip: If your skillet is a little too full to mix everything easily, feel free to transfer the sauce and pasta into a large mixing bowl before adding the cheese. You want to avoid any spills, and it’s totally fine to make it easier on yourself.

STEP 5: Transfer and Top

Once everything is well mixed, pour the spaghetti and sauce mixture into a greased 9×13-inch baking dish. Spread it out evenly with a spatula.

Then, sprinkle the grated Parmesan cheese all over the top. This is what gives the casserole that deliciously golden, crisp crust as it bakes.

Optional Upgrade: If you love a little crunch, try topping the casserole with a handful of crushed buttery crackers or crispy fried onions before baking. It adds a whole new texture that’s absolutely irresistible.

STEP 6: Bake to Perfection

Slide your baking dish into the preheated oven (set at 350°F) and bake uncovered for about 25 to 30 minutes. You’ll know it’s ready when the edges are bubbling, the top is golden brown, and your kitchen smells like something straight out of a Southern potluck dream.

Tip: If the top isn’t quite as golden as you’d like after 30 minutes, pop it under the broiler for 2 to 3 minutes. Just keep a close eye on it—Parmesan can go from golden to burned in a flash!

STEP 7: Rest and Garnish

Once baked, remove the casserole from the oven and let it rest for about 5 to 10 minutes. This helps the sauce thicken slightly and makes it easier to serve.

Sprinkle with chopped parsley if you’re feeling fancy (or if you want a pop of color), then dive in.

Helpful Tips and Flavor Variations

Making a casserole is often about convenience and comfort, and this recipe gives you a lot of flexibility. Here are a few ways to adjust or upgrade your spicy chicken spaghetti casserole based on what you have on hand or what your tastebuds are craving:

• Chicken Options: Rotisserie chicken is your best friend here. It’s fast, flavorful, and super tender. But if you’ve got leftover grilled chicken or roasted thighs, those work too.

• Pasta Swaps: Spaghetti is traditional, but don’t be afraid to sub in linguine, fettuccine, or even penne.

• Spice Control: You can dial the heat up or down depending on your crowd. Omit the cayenne for a milder version or toss in some sliced jalapeños for an extra punch.

• Cheese Choices: Cheddar and Parmesan are classic, but pepper jack or Monterey Jack add even more creaminess and spice.

• Make Ahead: Assemble the casserole up to a day ahead, cover it tightly, and refrigerate until you’re ready to bake. You may need to add 5-10 minutes to the bake time if it’s going in cold.