Brown beef and sausage in a large skillet over medium-high heat, breaking up meat; drain excess fat.
Mix ricotta, eggs, 1 cup mozzarella, 1/2 cup Parmesan, Italian seasoning, garlic powder, and salt well in a medium bowl.
Spray a 6-quart slow cooker's interior with cooking spray; spread 1 cup marinara in bottom.
Layer one-third of broken noodles, one-third of meat, one-third of ricotta mixture, and one-third of crushed tomatoes.
Repeat two more times; spread remaining marinara over top.
Sprinkle with remaining 1 cup mozzarella and 1/2 cup Parmesan. Cover; cook on low 4 hours, until noodles are tender.
Turn off cooker; rest 15 minutes, garnish with basil, and serve.