Preheat oven to 350 degrees. Spray a 9x13 pan with cooking spray.
In a large bowl, combine cake mix, eggs, oil, and 1 can of crushed pineapple with the juice. Mix well.
Pour into prepared baking pan and bake for 25-30 minutes, or until toothpick inserted in center of cake comes out clean. Allow to cool completely on a wire rack.
In a medium sized bowl, fold together whipped topping, box of vanilla pudding, and 1 can crushed pineapple with the juice. Spread over the top of cooled cake. Enjoy!
Video
Notes
*I reserve a small amount of pineapple from the can used for the frosting to sprinkle on at the end. This is optional, though!