Preheat oven to 350°F (175°C).

Prepare yellow cake mix according to package directions.

Bake cake in a 9 x 13-inch pan for the time indicated on the cake mix instructions, or until a toothpick inserted into the center comes out clean.

Let the cake cool completely.

In a mixing bowl, combine instant vanilla pudding, cream cheese, and milk.

Mix well until smooth and creamy.

Refrigerate the pudding mixture until it thickens and becomes easy to spread.

Spoon the pudding mixture evenly over the cooled cake.

Sprinkle crushed pineapple over the pudding layer.

Spread Cool Whip evenly over the pineapple layer.

Sprinkle coconut flakes and chopped nuts evenly over the Cool Whip.

Refrigerate for at least 30 minutes before serving to allow the flavors to meld.

Cut into squares and serve chilled.