Mix together 2 cups of powdered milk, 1/4 cup cocoa, 1 cup powdered sugar and a dash of salt. You can use a sugar substitute, if desired. For a richer mix, add 1/3 cup powdered non-dairy cream and/or a tablespoon or 2 or malted milk powder to the above mixture. To use, put about 4 tablespoons of the mix, use more or less to suit taste, into a cup of boiling water. Add a dash of whipped topping or vanilla ice cream if desired.