Heat the oil in a large pot or large saute pan over medium-high heat. Add the ground beef and sprinkle with the Italian seasoning, chili powder, salt, black pepper, and crushed red pepper (if using). Stir well to combine.
Arrange the beef in one layer and cook for 2-3 minutes. Stir well. Continue cooking for 1-3 minutes until the meat is browned. Stir often and break up large pieces with a wooden spoon or spatula.
Lower the heat to medium and add the onions, cook for 3 minutes, stirring frequently.
Next, add the garlic and tomato paste, cook for 1-2 minutes, stir often.
Add the pasta sauce, diced tomatoes, beef broth, and Worcestershire sauce to the pan. Stir well to combine.
Raise the heat to high and bring the sauce to a simmer. Then, lower the heat to medium-low, cover the pan and simmer for 30 minutes to let the flavors develop and come together.
In the meantime, cook the macaroni following the package directions for al dente.
Preheat the oven to 350°F.
Combine the cooked macaroni with the sauce.
Add half the beef and macaroni to a baking dish that is at least 11x7½ inch (2.5 quarts).
Sprinkle the top with half (4 ounces) of the shredded cheese.
Add the remaining macaroni beef mixture.
Top with the remaining cheese.
Bake the macaroni and beef casserole for 20-25 minutes or until bubbly on the edges and the cheese is melted.
Remove the casserole from the oven and let it set for 10-15 minutes before serving.