Bring a large pot of water to a boil, salt it, add the pasta and cook until al dente. Drain.
While the pasta is working, in a large skillet, heat the EVOO, 2 turns of the pan, over medium heat. Add the beef, crumbling it into bits, and cook until lightly browned, 3 to 4 minutes. Add the carrot, onion and garlic; season with salt and pepper. Cook until the vegetables are softened, 5 minutes. Stir in the beef broth, then the tomatoes and basil; simmer.
In a small bowl, stir together the ricotta and parsley.
Toss the pasta with the butter, then stir in the parmigiano-reggiano and meat sauce. Scoop the ricotta mixture into each of 4 shallow bowls, then top with the meaty pasta. Pass more parmigiano-reggiano around the table.