Pour half of the pasta sauce into the bottom of the crockpot. Add the frozen ravioli and pour the remaining pasta sauce and tomato sauce over the ravioli. Top with red bell pepper and Italian seasoning to taste. Mix well and cover.
Turn the crockpot on low and cook for 4-5 hours or until the ravioli are tender. During the last 20 minutes of cooking top with mozzarella cheese and cook until it has melted.