Add sugars and cocoa to melted butter, blend well. Beat in eggs one at a time. Sift flour and baking powder into mixture, stir. Add vanilla and walnuts stir until mixed. Bake in 9 x 13 pan for 30 mins in a 350 Degree oven.
Put butter, sugar and cocoa in food processor, mix well. Add liquid and blend until smooth. Ice brownies when cooled.