Coca-Cola cake is one of the moistest cakes you will ever eat not to mention the best fudge icing ever.   What is in this Coca-Cola cake?  Cake mix, cocoa powder, butter, Coca-Cola, buttermilk, eggs, vanilla, and marshmallows.   What is in this amazing fudge icing? Butter, cocoa powder, Coca-Cola, confectioners sugar and Southern pecans.  DELICIOUS