Spray interior of slow cooker thoroughly with nonstick cooking spray.
Prepare meatballs. In a large bowl and with hands, mix together all meatball ingredients. Roll into balls 1-inch or 1 1/2-inches in diameter. Drop onto a baking dish lined with waxed paper. Cover with aluminum foil and set in refrigerator at least 30 minutes.
Mix together sauce ingredients in a medium bowl. Set aside.
Place meatballs in slow cooker, stacking them one on another. Pour sauce over meatballs.
Place the lid on top of the slow cooker and allow the meatballs to cook for 6 to 8 hours. Meatballs are ready when the internal temperature of each one has reached 165 degrees Fahrenheit, determined by a meat thermometer. Basting, if desired during cooking time (careful not to let heat out from slow cooker)
Serve warm either on small appetizer plates or with toothpicks for guests to pick meatballs out from the slow cooker.