Cookie * 1/2 lb butter, plus * 1 tablespoon butter * 1 cup Sugar * 2 cups flour * 1 1/2 cups shredded sweetened coconut * 2 ounces semisweet baking chocolate, melted * 1/2 cup boiling water * 1 teaspoon baking powder butter cream filling * 1 lb confectioners' Sugar, divided * 1/4 lb butter, softened (not melted!) * 1/8 teaspoon salt * 1 teaspoon vanilla extract * 3-4 tablespoons milk