Preheat the oven to 350°F (175°C). Grease and flour a 9x13 inch baking dish.

In a mixing bowl, combine the yellow cake mix, water, vegetable oil, and eggs. Mix until well combined.

Pour the batter into the prepared baking dish and bake for 30 minutes or until a toothpick inserted in the center comes out clean.

While the cake is baking, mix the crushed pineapple with juice, instant vanilla pudding mix, and milk in a separate bowl.

Once the cake is done, remove it from the oven and let it cool for 10 minutes.

Using a toothpick, poke holes all over the top of the cake.

Pour the pineapple mixture over the warm cake, spreading it evenly.

Allow the cake to cool completely in the refrigerator for at least 2 hours.

Spread the whipped cream over the top of the cake and garnish with toasted coconut.

Slice and serve chilled.