1Spray 5- to 6-quart slow cooker with cooking spray. In 12-inch skillet, cook sausage, beef, onions, carrots and garlic over medium-high heat 8 to 10 minutes, stirring occasionally, until sausage and beef are thoroughly cooked; drain.
2In slow cooker, stir together meat mixture, tomatoes, tomato paste, vinegar, brown sugar, salt, pepper and pepper flakes.
3Cover; cook on Low heat setting 8 hours.
4About 15 minutes before serving, cook and drain spaghetti as directed on package. Serve meat mixture over spaghetti. Sprinkle individual servings with cheese and basil.