You can either serve them like this, as two separate cakes, or place both in the fridge to chill for 1 hour, then carefully remove one from the cake board stack on top of the other.
* A cold bowl will help the frosting whip up better. ** Do not skimp on this! It takes a long time, but this is what helps give it the proper texture. *** You will have a bit of frosting left over. You can use this to add more frosting to the cake if desired, or spoon into small bowls and serve as mousse.