01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan thoroughly.
02 - Combine yellow cake mix, eggs, crushed pineapple with juice, vegetable oil, and water in a large bowl. Beat until completely smooth and well blended.
03 - Pour batter into prepared pan. Bake for 28-32 minutes until a toothpick inserted in the center comes out clean.
04 - Let cake cool for 10 minutes. Using the handle of a wooden spoon, poke holes evenly across the entire cake surface, spacing approximately 1 inch apart.
05 - Whisk together sweetened condensed milk and coconut milk in a medium bowl until fully incorporated. Slowly pour evenly over the warm cake, allowing liquid to absorb into the poked holes.
06 - In a separate bowl, whisk together instant vanilla pudding mix, cold milk, and pineapple juice. Continue whisking for approximately 2 minutes until pudding begins to thicken. Spread evenly over the cake.
07 - Cover cake with plastic wrap or foil. Refrigerate for at least 1 hour until completely chilled and set.
08 - Spread thawed whipped topping evenly over the entire surface of the chilled cake.
09 - Sprinkle toasted shredded coconut generously over the whipped topping. Garnish with fresh pineapple chunks and maraschino cherries if desired.
10 - Slice into squares and serve cold. For best results, keep refrigerated until ready to serve.