Preheat oven to 350°. Pour oil into 13×9 cake pan, covering the bottom. Add cake mix, eggs and water to pan. Stir until blended (it will still be lumpy, just get the big cake mix chunks broken up but don’t stress about the little ones.) Scrape sides of pan and spread evenly.

Spoon pie filling onto batter, and fold in enough to marble. Sprinkle sugar liberally on top to make a crunchy crust (you can also mix cinnamon into the sugar first.)

Bake for 40-50 minutes. The cake should still be soft but not doughy. Good hot or cold.