In a large bowl, beat the eggs, sugar, oil and vanilla. Combine the flour, cinnamon, baking soda and salt; add to egg mixture and mix well. Fold in apples and nuts. Pour into a greased 13x9-in. baking dish. Bake at 350° for 55-60 minutes or until a toothpick inserted in the center comes out clean. Cool on a wire rack., In a small bowl, beat cream cheese and butter. Add confectioners' sugar, beating until smooth. Spread over cake. Refrigerate leftovers.