Cake: Cream the butter and sugar; add sweet potatoes and beat until light and fluffy. Add the eggs one at a time beating well after each. Combine the dry ingredients and stir into creamed mixture; add vanilla, nuts and coconut. Pour the mixture into greased 10 inch tube pan and bake at 350ºF. for 1 hour 15 minutes or until cake tests done. Spread with icing while warm. Icing: Combine all of the icing ingredients, slowly adding enough orange juice to make spreading consistency.