In saucepan put water, cocoa, and margarine. Boil, then remove from heat. Add cinnamon, soda, sugar and vanilla. In a separate bowl, beat milk, eggs and vinegar. Add this to chocolate mixture, then add flour. Pour into greased cookie sheet or sheetcake pan. Bake at 180ÂșC for 30 minutes. Frosting. In saucepan put margarine, cocoa, milk, vanilla and confectioners' sugar to warm only. Prick hot cake all over with fork and pour warm icing all over. I make this often...it's easy and GOOD! YUM! Kay. ----