I am making a graduation cake for a friend of the family.  The grad wants whipped frosting.  I explained to him that that won't work with fondant and the decorations he wanted.  He then asked if it could go between the layers.

So what can I use and how do I do it so it doesn't just squish out the sides or just be absorbed into the cake making a wet mess??

I have searched the recipes but I am just clueless on this - or over thinking it and becoming brain dead - lol

TIA

Do you want to do whipped heavy whipping cream, or non dairy whip topping? If it is heavy whipping cream then what I do is whip cream cheese with condensed milk until well blended then add heavy whipping cream and whip until stiff. I put a thicker layer if this filling because it settles down a little after a couple of hours. 

Probably non-dairy as it will be sitting out for 6-9 hours.  Temps for the day will be 76 and though the cake will be inside, the doors and windows will be open. 

Will I dam it with the regular b/c that I frost the outside of the cake with to keep it from squishing and causing the the dredged fondant bulge?   Never had much luck with "damming" helping in this.

Sorry, can`t help you on fondant, dam or bc. I am working with non dairy whip topping called Whip `n Ice I use it for icing and decorating my cakes it`s non dairy. As for filing in cake I work a lot with heavy whipping cream but its not going to work if cake will sit out for so long. Maybe try some recipes with Cool Whip? There is one I have it has cream cheese , sugar, sourcream and Cool Whip. If you want to try it I can pm you a recipe.

Yes please do.  Maybe one will work.  I would like to try something that would give him what he wants, or at least tell him I gave it a good try.