Need advice on sponge cake layers with mousse-like filling

[merstar]

I want to make the Mexican Chocolate Icebox Cake from Bon Appetit - I've made it many times, and it's great, but this time, I want to use two sponge cake layers instead of the ladyfingers. Do you think the top layer would squish the filling? (there's no gelatin in the filling). I don't want to split them, and each layer has 3/4 cup flour - they're made in 9-inch rounds. Here are the ingredients of the cake I'm considering:
6 large eggs, separated
1 cup sugar
1½ cups bleached AP flour
2 tsp. baking powder
¼ tsp. salt
1 tsp. vanilla

Here's a link to the cake:
http://www.epicurious.com/recipes/food/views/101955

 

[bakechef]

That recipe should produce a very light cake. The layers should be relatively thin too, I think that it would work.

A traditional American style sponge of similar size in 2 9" pans would have anywhere from 2 1/2-3 1/2 cups flour. This has half and will get a majority of its volume from the whipped egg whites.

 

[merstar]

Thanks! For extra reassurance, I think I'm going to freeze or semi-freeze it before adding the top layer.