Beat eggs with a mixer until thick and light. Combine sugar and oil; pour into eggs with mixer on medium speed. Stir together flour, cinnamon, soda and salt; add to egg mixture with vanilla; beat to mix. Stir in walnuts. Spread apples in a buttered 13 x 9 x 2-inch pan. Pour batter over apples, spreading to cover. Bake in a 350 degrees oven for 1 hour. Remove from oven and cool. Cream Cheese Icing: Mix two 3-ounce packages cream cheese, 1/4 cup melted butter, 2 cups powdered sugar and 1 teaspoon lemon juice. Spread on cake.