In a large skillet, over medium-high heat, cook ground beef, garlic, garlic powder, salt, and pepper until meat is browned and crumbly; drain. Add pasta sauce and Italian seasoning to the beef mixture.
Place 3/4 cup of meat sauce into bottom of slow cookier; add a layer of frozen ravioli followed by a layer of meat sauce. Continue layering until everything except cheese is used.
Cover, and cook on low 3-5 hours.
Sprinkle mozzarella cheese on top of ingredients; cover and cook an additional 30-45 minutes on low until cheese is melted.
