Preheat oven to 350°F. Grease a 13x9-inch baking dish.
Make 1 white cake mix according to package directions (including the eggs, oil, and water as listed), adding an 8 oz can crushed pineapple (including the juice) to the batter.
Bake according to package directions in a 13x9-inch pan.
After you remove it from the oven, use a straw or fork to poke holes into the warm cake. Pour a 15 oz can cream of coconut over the warm cake. Place in the refrigerator to cool completely.
While the cake is cooling, toast 1 cup shredded coconut by spreading it onto a sheet pan. Bake for 5–10 minutes at 350°F, stirring every 3 minutes so it toasts evenly.
For the topping, mix together 8 oz Cool Whip, 3 oz box instant vanilla pudding, and 8 oz can crushed pineapple (including the juice). Spread over the fully cooled cake and top with toasted shredded coconut. Refrigerate until ready to serve.
