01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan thoroughly with cooking spray or butter.
02 - In a large mixing bowl, combine yellow cake mix, eggs, crushed pineapple with juice, vegetable oil, and water. Beat with electric mixer on medium speed until smooth, about 2 minutes.
03 - Pour batter into prepared pan and spread evenly. Bake for 28-32 minutes or until a toothpick inserted in the center comes out clean.
04 - Let cake cool in pan for 10 minutes. Using the handle of a wooden spoon, poke holes all over the surface of the cake, spacing about 1 inch apart.
05 - Whisk together sweetened condensed milk and coconut milk until well combined. Slowly pour mixture evenly over warm cake, allowing it to soak into the holes.
06 - In a separate bowl, whisk together instant vanilla pudding mix, cold milk, and pineapple juice until thickened, about 2 minutes. Spread pudding evenly over the cake.
07 - Cover pan with plastic wrap and refrigerate for at least 1 hour, or until completely chilled and set.
08 - Spread thawed whipped topping evenly over the chilled cake using an offset spatula.
09 - Sprinkle toasted coconut over the top. Garnish with fresh pineapple chunks and maraschino cherries if desired. Slice into squares and serve cold.