Bake cake mix according to package directions for two layers, let cakes cool.

Prepare the pudding according to package with the 5 cups of milk.

Arrange half of the cake pieces in the bottom of a large punch bowl. Spread with half of the pudding, then top with sliced bananas, drained pineapple, pie filling, and half of the coconut.

Repeat in the same order with the remaining ingredients.

Top with whipped topping, then sprinkle with chopped walnuts. Chill and serve.