Million Dollar Spaghetti Casserole is the ultimate comfort dish—layers of creamy Alfredo-coated spaghetti, hearty seasoned meat sauce, and gooey melted cheese baked to perfection. Rich, filling, and crowd-pleasing, this casserole is perfect for family dinners, potlucks, or make-ahead meals.
Ingredients
- 1 pound (16 ounces) spaghetti noodles, cooked al dente
- 1 pound lean ground beef
- 1 small onion, finely diced
- 1 green bell pepper, finely diced
- 2 teaspoons Cajun seasoning
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- 1 teaspoon dried Italian seasoning
- 1 (24-ounce) jar marinara sauce
- 1/2 cup (1 stick) unsalted butter
- 4 cloves garlic, minced
- 2 cups heavy cream
- 2 1/4 cups shredded Parmesan cheese, divided (2 cups for Alfredo, 1/4 cup for topping)
- 1/2 teaspoon kosher salt
- 1/2 teaspoon black pepper
- 2 cups shredded mozzarella cheese
- 2 teaspoons dried parsley flakes, for garnish (optional)
Instructions
Preheat your oven to 350°F (175°C). Lightly spray a 9×13-inch baking dish with cooking spray and set aside.
Cook the spaghetti: If you haven’t already, cook 1 pound of spaghetti noodles according to package directions until al dente. Drain well and set aside.
Prepare the meat sauce: In a large skillet over medium-high heat, add the ground beef, diced onion, diced green bell pepper, Cajun seasoning, garlic powder, onion powder, and dried Italian seasoning. Break up the beef with a spoon and cook, stirring occasionally, until the beef is no longer pink and the vegetables have softened, about 10 minutes.
Drain any excess grease from the skillet. Stir in the 24-ounce jar of marinara sauce. Reduce the heat to low and let it simmer for 15 minutes, stirring occasionally, allowing the flavors to meld.
While the meat sauce simmers, make the Alfredo sauce: In a Dutch oven or large stockpot, melt 1/2 cup (1 stick) unsalted butter over medium heat. Add the minced garlic and cook for 30 seconds until fragrant.
Stir in the 2 cups heavy cream, 2 cups shredded Parmesan cheese, 1/2 teaspoon kosher salt, and 1/2 teaspoon black pepper. Continue to cook, stirring frequently, until the cheese has melted and the sauce has thickened slightly. Do not boil.
Combine spaghetti and Alfredo: Add the cooked and drained spaghetti directly into the Alfredo sauce in the Dutch oven. Toss until the noodles are completely coated in the creamy sauce. Pour this mixture evenly into the prepared 9×13-inch baking dish.
Layer the meat sauce: Carefully spoon the simmering meat sauce evenly over the Alfredo-coated spaghetti in the baking dish.
Top with cheese: Sprinkle the 2 cups shredded mozzarella cheese and the remaining 2 tablespoons shredded Parmesan cheese evenly over the meat sauce layer.
Bake: Bake uncovered for 15 minutes, or until the cheese is melted, bubbly, and lightly golden.
Garnish and serve: Garnish with 2 teaspoons dried parsley flakes (if using) and serve hot. Enjoy!
Health Benefits
- High in protein from ground beef and cheese, supporting muscle repair
- Calcium-rich thanks to Parmesan and mozzarella for bone health
- Energy-boosting carbohydrates from spaghetti for sustained fuel
- Home-cooked control over ingredients and seasoning compared to store-bought casseroles
