• Preheat the oven to 350 degrees Fahrenheit. Spray a 9 x 13 x 2 or 3-inch baking dish with nonstick cooking spray.

Spaghetti Layer

• Toss 12 ounces spaghetti noodles cooked until al dente in a bowl with 1 cup marinara sauce until the noodles are coated.

Meat Layer

• Add 1 tablespoon olive oil to a large 14-inch skillet and heat over medium-high heat. Add 1 pound lean ground beef and ½ pound ground mild Italian sausage and cook until the meat is no longer pink, about 7-10 minutes. Drain any grease.
• Add ¼ cup diced onion and 1 teaspoon minced garlic and cook for 3-4 minutes or until the onion is soft and translucent.
• Turn off the heat and stir in 4 cups jarred marinara sauce, 1 teaspoon Italian seasoning, and salt and ground black pepper to taste.

Creamy Cheese Layer

• Add 8 ounces softened cream cheese, ⅓ cup sour cream, 1 cup ricotta cheese, 1 cup shredded mozzarella cheese, and ½ cup grated parmesan cheese to a medium bowl and mix until evenly combined.

Assembly

• Add the spaghetti mixture to the bottom of the prepared baking pan.
• Evenly distribute ¼ cup sliced salted butter on top of the noodles. Spread the million dollar mixture and top of the noodles.
• Add the meat sauce on top of the million dollar mixture, then sprinkle 1 ½ cups shredded mozzarella cheese evenly over the top.
• Cover with aluminum foil and bake for 30 minutes. Remove the foil bake for an additional 10 minutes until the cheese is melted and browned.