Add olive oil to a large dutch oven and set over medium heat. Once the olive oil is shimmering, add onions, carrots and celery and cook for 7 to 9 minutes, or until the vegetables have softened and the onion is translucent.
Add garlic, Italian seasoning, salt, pepper and crushed red pepper, and cook for 1 to 2 minutes, or until the garlic is very fragrant.
Add the ground beef, breaking it up with a spatula, and cook for about 5 minutes, or until no longer pink. Add tomato paste, stirring to incorporate it into the meat and vegetables, and cook for 2 minutes.
Add the diced tomatoes, marinara sauce and vegetable broth and bring to a boil. Reduce heat to a simmer and cook for 15 to 20 minutes, or until the vegetables are very soft.
Once the vegetables have softened, return the soup to a boil and add lasagna noodles. Cook at a gentle boil for 8 to 10 minutes, or until the pasta is al dente.
Serve the soup in large bowls topped with a dollop of ricotta, grated Parmesan and a sprinkle of fresh basil.
Tip: Make a big batch of this lasagna soup minus the noodles for an easy dump-and-heat freezer meal for busy weeknights!