1Cook beef and onion in 12-inch skillet over medium-high heat about 8 minutes, stirring frequently, until beef is brown; drain.
2Spray 3 1/2- to 4-quart slow cooker with cooking spray. Spoon beef mixture into cooker. Stir in bell pepper, pizza sauce, pepperoni, basil and oregano.
3Cover and cook on low heat setting 4 to 6 hours.
4Serve beef mixture with buns and cheese. Beef mixture will hold on low heat setting up to 4 hours.