Preheat oven to 350°F (180°C).

In a large bowl, combine yellow cake mix, margarine, beaten eggs, mandarin oranges with juice, crushed pineapple with juice, and vanilla pudding mix.

Beat the mixture for 5 minutes until well combined.

Pour the batter into a greased and floured 9x13 inch pan.

Bake for 30 minutes, or until a wooden skewer inserted into the center comes out clean.

Let the cake cool completely in the pan.

Drain the crushed pineapple, reserving the juice.

In a separate bowl, combine the pineapple juice with the dry vanilla pudding mix.

Beat until the pudding thickens.

Gently fold in the prepared whipped topping.

Fold in the drained crushed pineapple.

Frost the cooled cake with the pineapple-pudding-whipped topping mixture.

Refrigerate the frosted cake until ready to serve.