Cream butter in large mixing bowl. Gradually add sugar; beat until light and fluffy. Add eggs; beat well. Sift flour with soda, cinnamon, nutmeg and salt; add to creamed mixture. Mix well. Stir in apples and nuts. Pour into greased and floured 9x13 inch pan. Bake at 350 for 15 minutes, then reduce heat to 300 for 45 minutes more. (Mixture will be hard to mix.)
Icing-combine ingredients in saucepan. Cook over low heat, stirring constantly. Bring sauce to boil, then cook for 1 minute. Pour over cake evenly.