Cake
Sift flour and sugar in bowl. Heat butter, coca and cola to boiling point. Pour over flour and sugar mixture. Add rest of the ingredients except marshmallows. Beat until smooth. Add marshmallows. Batter will be thin and marshamallows will float to top. Bake in oblong pan, 30-35 minutes at 350 degrees.
Icing: Heat butter, coca and cola to boiling point, pour over sugar, beat and add nuts and vanilla. Ice cake while hot.