Melt the butter in a large saute pan. Add the onions and cook over medium heat, stirring occasionally until caramelized and golden brown. Add the 2 Tablespoons water and cook until the water has evaporated, about 3 minutes. Remove the onions to a cutting board to cool slightly. After the onions have cooled , coarsely chop them.Place the sour cream, cream cheese, parsley, onion powder and worcestershire sauce in a large bowl. Stir until the mixture is smooth. Add the onions and salt and pepper to the bowl , stir until well incorporated. Serve at room temperature.