Preheat oven to 350 degrees F (175 C). Grease and flour one 9x13 inch cake pan.
In a mixing bowl; beat oil and eggs with an electric mixer until creamy. Add the sugar and vanilla and beat well..
Combine the flour salt, baking soda, and cinnamon together in a bowl. Slowly add this mixture to the egg mixture and mix until combined. The batter will be very thick. Fold in the apples by hand using a wooden spoon. Spread batter into the prepared pan.
Bake at 350 F (175 C) for 45 minutes or until cake tests done. Let cake cool on a wire rack