Chicken Spaghetti (Creamy Baked Casserole-Style)

What Makes This Recipe Work

Tossing the hot spaghetti with the sauce before it goes into the baking dish seasons every strand instead of just the top layer. Sour cream plus cream of chicken soup gives body without a flour-based roux, so the casserole reheats without breaking.

Ingredients for Chicken Spaghetti (Creamy Baked Casserole

• 12 oz (340 g) spaghetti
• 4 cups (about 1 lb / 450 g) shredded cooked chicken (1 rotisserie chicken)
• 2 tbsp butter
• 1 small yellow onion, finely diced
• 2 garlic cloves, minced
• 1 (10.5 oz / 300 g) can cream of chicken soup
• 1 cup (240 ml) sour cream
• 1 (10 oz / 285 g) can diced tomatoes with green chiles, drained
• 1 cup (240 ml) chicken broth
• 2 cups (200 g) shredded cheddar or Monterey Jack, divided
• 1/2 tsp kosher salt and 1/2 tsp black pepper
• 2 tbsp chopped fresh cilantro or parsley, for serving

How to Make Chicken Spaghetti (Creamy Baked Casserole

1. Heat the oven to 375°F (190°C) and lightly butter a 9x13 baking dish.
2. Cook the spaghetti in well-salted water 1 minute under package directions so it finishes softening in the oven; drain and return it to the pot.
3. Meanwhile, melt the butter in a skillet over medium heat, add the onion, and cook until softened, 5 to 6 minutes; add the garlic and cook 30 seconds more.
4. Stir the cream of chicken soup, sour cream, drained tomatoes, chicken broth, salt, and pepper into the skillet until smooth and heated through.
5. Pour the sauce over the hot spaghetti, add the shredded chicken and 1 cup of the cheese, and toss until everything is evenly coated.
6. Transfer the mixture to the prepared baking dish, spread it flat, and top with the remaining cheese.
7. Bake 20 to 25 minutes until the casserole is bubbly around the edges and the cheese is fully melted.
8. For a browned top, broil 2 minutes watching closely, then rest 5 minutes and scatter with cilantro or parsley before serving.

Tips for the Best Chicken Spaghetti (Creamy Baked Casserole

• Use a whole rotisserie chicken and shred it while still slightly warm; cold shredded chicken does not absorb the sauce as well.
• Undercook the pasta by about a minute. It absorbs liquid in the oven, and fully cooked spaghetti turns soft and clumpy.
• Drain the diced tomatoes well so the casserole does not go soupy under the cheese.
• Shred the cheddar from a block; pre-shredded cheese melts more slowly and can leave an oily finish on top.

Variations and Substitutions

• Swap the cheddar for pepper jack and keep the green chiles for a spicier bake.
• Use half spaghetti and half penne if you prefer a short pasta that scoops more easily.
• For a richer twist, stir 1/2 cup of the sauce base into a batch of italian meatballs and serve them alongside.
• Leftover roast chicken works exactly like rotisserie; for a beefy casserole night, pair the table with slow cooker pot roast-style sides.

How to Store and Reheat

• Leftover chicken spaghetti keeps covered in the fridge for up to 4 days; reheat portions in a 325°F (160°C) oven or microwave with a splash of broth to loosen the sauce.
• Assemble the casserole unbaked, cool, wrap tightly, and freeze up to 3 months; bake covered from frozen at 375°F for about 50 minutes, then uncover to brown the cheese.

Chicken Spaghetti (Creamy Baked Casserole FAQ