In a large skillet, cook sausage and onion over medium heat for 7-8 minutes or until sausage is no longer pink and onion is tender. Add garlic; cook 1 minute longer. Drain. Transfer to a 3-qt. slow cooker., Stir in the tomatoes, tomato sauce, tomato paste, brown sugar, bay leaves, oregano, dried basil, salt and thyme. Cover and cook on low for 6-8 hours., Discard bay leaves; stir in half of the fresh basil. Serve with pasta. Top with remaining basil.