• Preheat the oven to 375 degrees Fahrenheit. Spray a 9 x 13-inch baking dish with nonstick cooking spray and set aside.
• Bring a large pot of salted water to a rolling boil, then cook 1 (12-ounce) box jumbo shell pasta according to the directions on the package for al dente pasta. If preferred, undercook by a few minutes to avoid overcooking in the oven.
• Drain the shells and rinse them with cold water to stop the cooking process. Toss lightly with 1-2 teaspoons of olive oil or vegetable oil to prevent them from sticking.

Sauce

• Add ½ pound lean ground beef and ½ pound mild Italian sausage to a large skillet and cook over medium heat for 7-10 minutes until fully browned and no pink remains, breaking up the meat into crumbles as it cooks. Drain off any excess grease.
• Add 1 tablespoon olive oil and ⅓ cup diced onion to the skillet, and cook for about 2 minutes before adding 2 teaspoons minced garlic. Cook for an additional minute, then stir in 3 cups marinara sauce and 1 teaspoon Italian seasoning. Season with salt and ground black pepper to taste and remove from the heat.

Million Dollar Cheese Filling

• Add 8 ounces softened cream cheese, 1 cup small-curd cottage cheese, ½ cup sour cream, 1 ⅓ cups of the 2 cups shredded mozzarella cheese, and ½ cup shredded parmesan cheese to a large bowl and mix until combined by hand or with an electric mixer.

Assembly

• Spread about ¾ of the sauce evenly in the bottom of the baking dish.
• Stuff the shells with about 2 tablespoons of the million dollar filling in each shell, then arrange them in an even layer over the top of the sauce.
• Spoon the remaining third of the sauce over the tops of the shells, and top with the remaining mozzarella cheese.
• Bake uncovered for 25-30 minutes, until the cheese is melted and bubbling. Let the dish rest for about 5 minutes before garnishing with chopped fresh parsley or basil if desired and serving.