Preheat the oven to 375°F (190°C).
Cook the elbow macaroni pasta in a large pot of boiling salted water according to package instructions until al dente. Drain and set aside.
While the pasta cooks, heat olive oil in a large skillet over medium heat.
Add the diced onion and sauté for 3-4 minutes until softened.
Add the minced garlic and cook for 1 minute until fragrant.
Add the ground beef to the skillet and cook, breaking it apart with a spoon, until browned and cooked through, about 6-8 minutes. Drain excess fat if necessary.
Stir in the marinara sauce, diced tomatoes with their juice, dried Italian seasoning, salt, and black pepper. Simmer for 5 minutes to combine flavors.
In a large mixing bowl, combine the cooked pasta, ground beef sauce mixture, and ricotta cheese. Mix well to evenly distribute the ingredients.
Transfer the mixture to a 9×13-inch baking dish and spread evenly.
Sprinkle shredded mozzarella cheese and grated Parmesan cheese evenly over the top.
Bake uncovered in the preheated oven for 20-25 minutes until the cheese is melted and bubbly.
Remove from the oven and let the casserole rest for 5 minutes before serving.