01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan thoroughly with cooking spray or butter.
02 - In a large bowl, combine yellow cake mix, eggs, crushed pineapple with juice, vegetable oil, and water. Beat with electric mixer on medium speed for 2 minutes until smooth and well incorporated.
03 - Pour batter into prepared baking pan. Bake for 28-32 minutes until golden brown and a toothpick inserted in the center comes out clean. Remove from oven and let cool for 10 minutes.
04 - Using the handle of a wooden spoon, poke holes all over the warm cake, spacing about 1 inch apart. Press holes about three-quarters of the way through the cake without reaching the bottom.
05 - In a medium bowl, whisk together sweetened condensed milk and coconut milk until completely smooth and combined.
06 - Slowly pour the milk mixture evenly over the warm cake, ensuring it fills the poke holes. Allow liquid to absorb for 5 minutes before proceeding.
07 - In a separate bowl, whisk together instant vanilla pudding mix, cold milk, and pineapple juice. Continue whisking for 2 minutes until pudding begins to thicken.
08 - Spread the thickened pudding evenly over the entire surface of the cake, covering all holes and creating a smooth layer.
09 - Cover pan tightly with plastic wrap or aluminum foil. Refrigerate for at least 1 hour, or until completely chilled and set. For best results, chill 2-3 hours or overnight.
10 - Spread thawed whipped topping evenly over the chilled cake. Sprinkle toasted coconut generously over the top. Arrange fresh pineapple chunks and maraschino cherries decoratively across the surface, if desired.
11 - Slice into 12 equal squares and serve cold. Store leftovers covered in the refrigerator for up to 3 days.