1. Preheat the oven to 350°F 175°C and lightly grease a 9×13 inch baking dish.

2. Bring a large pot of salted water to a boil. Add the pasta shells and cook according to package directions, stopping 1 to 2 minutes before al dente so the pasta stays firm when baked. Drain and set aside.

3. While the pasta cooks, heat the olive oil in a large skillet over medium high heat. Add the ground beef and diced onion and cook, breaking up the meat with a spatula, until the beef is browned and the onion is softened.

4. Stir in the minced garlic, kosher salt, black pepper, smoked paprika, and onion powder. Cook for 30 to 60 seconds, just until the garlic is fragrant.

5. Pour in the tomato sauce, ketchup, yellow mustard, and Worcestershire sauce. Stir well and bring the mixture to a gentle simmer.

6. Reduce the heat to low and add the cream cheese pieces. Stir until the cream cheese is completely melted and the sauce is smooth, then whisk in the sour cream. Taste and adjust the seasoning if needed.

7. In a large mixing bowl or the empty pasta pot, combine the cooked pasta with the cheeseburger beef sauce. Stir in 1 cup of the shredded cheddar cheese and 0.5 cup of the shredded mozzarella so some cheese melts throughout the casserole. Fold in most of the chopped dill pickles if using, reserving a spoonful for topping.

8. Transfer the mixture to the prepared baking dish and spread it into an even layer. Sprinkle the remaining 1 cup cheddar and 0.5 cup mozzarella evenly over the top. Add the reserved chopped pickles if desired.

9. Bake for 20 to 25 minutes, or until the casserole is bubbly around the edges and the cheese on top is melted and lightly golden.

10. Let the casserole rest for 5 to 10 minutes before serving so it can set slightly. Garnish with chopped fresh parsley or green onion, scoop into bowls or onto plates, and enjoy.