COMBINE FLOUR, SUGAR, SALT AND COCOA IN A LARGE BOWL. MIX IN A SAUCE PAN, WATER, OIL AND BUTTER. BRING TO A BOIL. POUR INTO DRY MIX AND BEAT UNTIL SMOOTH. ADD BUTTERMILK, EGGS AND SODA. BEAT; BATTER WILL BE THIN. POUR INTO WELL GREASED JEELY ROLL PAN. COOL ON A WIRE RACK; WHILE STILL A LITTLE WARM, FROST WITH ROCKY ROAD FROSTING (SEE RECIPE ON PAGE XX).