Preheat oven to 350°F (175°C).

Combine white cake mix, eggs, cooking oil, and undrained mandarin oranges in a large bowl.

Blend on low speed for 2 minutes.

Grease and flour two layer cake pans.

Pour batter evenly into the prepared pans.

Bake in preheated oven for 33 to 38 minutes, or until a wooden skewer inserted into the center comes out clean.

Let the cakes cool in the pans for 10 minutes before inverting onto a wire rack to cool completely.

While the cakes are cooling, mix vanilla instant pudding mix with milk until thick.

Drain crushed pineapple.

Add drained pineapple and Cool Whip to the pudding mixture and stir gently to combine.

Once the cakes are completely cool, spread the pudding mixture between the layers and on top of the cake.

Refrigerate for at least one hour before serving to allow the flavors to meld and the frosting to set.