1 Preheat oven to 350 degrees F (175 degrees C). Grease a 9×13 inch pan.
2 In prepared pan, combine cake mix, oil and water. Stir together until cake mix is moistened, breaking up any large lumps in the batter and spreading to cover bottom of pan. Spoon on pie filling to form strips evenly spaced over batter, but not too close to edge of pan. Gently fold batter over pie filling, creating a swirl pattern and spreading out to form an even layer.
3 Bake in the preheated oven for 40 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool.
4 For the topping: Mix together the crushed pineapple and instant pudding. Refrigerate for 5 minutes, or until thickened. Fold in whipped topping, then spread over cooled cake. Keep refrigerated until ready to serve.