Preheat your oven to 350°F and grease a 9x13 baking dish.
Using a large bowl or a stand mixer, blend the cake mix, pudding mix, oil, eggs, and undrained crushed pineapple.
Mix for approximately 2 minutes on medium-high speed until smooth.
Transfer the mixture into your baking dish, ensuring an even spread.
Bake for 35-40 minutes. The cake is ready when a toothpick inserted comes out clean. Cool thoroughly.