Place carrots, potatoes and water in a saucepan; cover and cook over medium heat until the vegetables are tender. Drain, reserving cooking liquid. In a skillet, saute onions and garlic in butter for 10 minutes. Add flour; cook and stir for 2 minutes. Place carrots, potatoes, onion mixture, salt and sugar in a blender or food processor; cover and puree until smooth, adding reserved cooking liquid as needed. Pour into a 3-qt. saucepan or Dutch oven. Stir in milk and heat through. Add cream and cayenne; heat through (do not boil). Garnish with paprika.