1Spray 6-quart slow cooker with cooking spray. In slow cooker, stir together parsnips, carrots, onions and cranberries. Top with sweet potatoes.
2In small bowl, stir together oil, vinegar, brown sugar, salt and pepper with whisk; pour over vegetables in slow cooker. (Do not stir.)
3Cover; cook on High heat setting 4 to 5 hours or until vegetables are tender. Sprinkle with parsley before serving.