Mix and bring to boil the coke, wesson oil, quarter cup of the butter, and quarter cup cocoa. Remove from heat and add the marshmallows, stir to melt. Mix together flour, baking soda, eggs, sugar, half cup butter and the vanilla. Add the coke mixture to the flour mixture and mix well. Pour in 13 x 23 cm pan and bake 30 to 35 minutes in a 350-degree oven. Meanwhile prepare icing: Heat coke and cocoa to a boil. Pour over sugar and mix well. Add nuts and pour over while cake and icing are still hot. ----