Bake the cake in two pans as directed on the box. Set aside to cool.
Prepare the pudding as directed on the package. Set aside I the refrigerator to set.
Once the pudding has set, cut 1 of the cakes into small cubes and transfer the cubes to a punchbowl.
Spread half of the pudding on top in an even layer.
Add half of the frozen strawberries in a single layer, half of the banana slices in a single layer, and half of the cool whip in an even layer.
Repeat with remaining ingredients, ending with a layer of the cool whip.
Cover the punch bowl with cling film and refrigerate overnight before serving.