Preheat oven to 350 degrees F (175 degrees C). Grease and four a 9x13 inch pan. In a medium bowl, mix together flour, baking soda, cinnamon and salt. Set aside.
Step 2
In a large bowl, combine eggs, oil and sugar. Beat until foamy. Add flour mixture and beat well. Add vanilla and stir in chopped apples and walnuts. Pour into a 9x13 inch pan.
Step 3
Bake for 45 to 50 minutes, or until a toothpick inserted into the cake comes out clean. Allow cake to cool, then spread with cream cheese frosting.
Step 4
To make the frosting: In a medium bowl, combine cream cheese, softened butter, confectioners sugar and 1 teaspoon vanilla. Beat until smooth, then spread on cake.