Prepare the Base:
In a skillet over medium heat, brown the ground beef until fully cooked. Drain excess fat and transfer the beef to the crockpot.
Add chopped onion and minced garlic to the skillet and sauté until softened, about 3-4 minutes. Transfer to the crockpot.
Combine Ingredients:
Add crushed tomatoes, tomato sauce, beef broth, water, dried basil, dried oregano, red pepper flakes (if using), salt, and pepper to the crockpot. Stir to combine.
Cook:
Cover and cook on low for 6-7 hours or on high for 3-4 hours.
Add Noodles:
About 30 minutes before serving, add the broken lasagna noodles to the crockpot. Stir to ensure the noodles are submerged in the soup. Cover and continue cooking until the noodles are tender.
Serve:
Ladle the soup into bowls and top each serving with a dollop of ricotta cheese, a sprinkle of mozzarella, and grated Parmesan cheese.
Garnish with fresh basil or parsley if desired. Serve hot and enjoy!