Mix and bring to boil the coke, wesson oil, 1/4 cup of the butter, and 1/4 cup cocoa. Remove from heat and add the marshmallows, stir to melt. Mix together flour, baking soda, eggs, sugar, 1/2 cup butter and the vanilla. Add the coke mixture to the flour mixture and mix well. Pour in 13 x 9" 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. ----