Brown the ground beef and onion in a skillet over medium-high heat, about 8 minutes. Add garlic for 1 minute. Drain, then stir in 1 teaspoon Italian seasoning, salt, and pepper.
In a bowl, mix cream cheese, ricotta, sour cream, ¼ cup Parmesan, and the remaining Italian seasoning until smooth.
Spray a 6-quart crock pot with nonstick spray.
Spread ½ jar marinara in the bottom. Layer half the pasta, the rest of the first jar of sauce, 1 cup water or broth, and half the beef.
Dollop the cheese mixture over the beef and spread gently. Do not stir.
Layer the remaining pasta, the second jar of marinara, the remaining 1 cup liquid, and the rest of the beef. Press down so the pasta is submerged.
Cover and cook on LOW 2½ to 3 hours or HIGH 1½ to 2 hours, until the pasta is tender. Start checking at 2 hours on LOW.
Stir gently. Top with mozzarella and remaining Parmesan, cover, and cook 10 to 15 minutes until melted.
Let rest uncovered 10 minutes. Garnish and serve.