Brown the Italian sausage in a large skillet over medium heat. Drain off any excess grease.

Add the onion and garlic to the skillet and cook until softened.

Transfer the sausage mixture to a slow cooker. Add the crushed tomatoes, tomato sauce, ricotta cheese, Parmesan cheese, and Italian seasoning.

Stir in the broken lasagna noodles.

Cover and cook on low for 6-8 hours or on high for 3-4 hours, or until the noodles are tender.

Stir in the fresh basil before serving.