In a large heavy pot or Dutch oven over medium-high heat, brown the sausage and ground beef, breaking it up as it cooks, about 8 to 10 minutes. Spoon off all but 1 to 2 tablespoons of the fat.

Add the onion and carrot and cook until soft, 5 to 6 minutes. If you pureed the carrot, let it cook until most of the liquid is gone and it just starts to caramelize. Add the garlic and cook for 30 seconds.

Push everything to the sides. Add the tomato paste and fennel seed to the middle and cook, stirring, for 4 to 5 minutes, until the paste turns brick-red and starts sticking to the bottom of the pot.

Pour in the beef broth and scrape up all the browned bits. Stir in the crushed tomatoes, tomato sauce, Italian seasoning, basil, thyme, oregano, rosemary, salt and pepper.

Bring to a bubble, then drop the heat to low. Partially cover and simmer for 1 1/2 to 2 hours, stirring every 15 to 20 minutes. Add a splash of broth if it gets too thick. It's ready when a spoon dragged across the bottom leaves a trail.

Turn off the heat. Stir in the red wine vinegar, then taste and add more salt if needed.

Heat the oven to 375°F. Boil the noodles 2 minutes less than the package directions. Drain and lay them flat so they don't stick together.

In a bowl, stir together the ricotta, egg, grated Parmesan, parsley, salt and pepper.

Spread about 1 cup of sauce in the bottom of a deep 9x13 baking dish. Add a layer of noodles, then one-third of the ricotta mixture, one-third of the mozzarella slices, a ladle of sauce and a sprinkle of Parmesan. Repeat two more times.

Top with the last noodles. Cover them edge to edge with sauce, then the remaining mozzarella and Parmesan.

Cover with foil, tented or sprayed with cooking spray so it doesn't stick to the cheese. Bake for 25 minutes. Remove the foil and bake 15 to 20 minutes more, until bubbling and browned on top.

Let it rest for 15 minutes. Sprinkle with parsley, slice and serve.