I would like to do a cake with ganache and a dulce deleche filling but was wondering a few things. Would the cake be able to be out over night without refrigeration as I want to cover it in fondant, and is it firm enough so that it wont leak out the sides?Anyone had any problems with it making the cake soggy?? Any suggestions would be appreciated.

I recently made a cake using Dawn's Vanilla Butter cake recipe, dulce de leche filling, chocolate ganache under chocolate fondant. It was really delicious. Dawns butter cake recipe is a very dense flavorful cake. I still made a dam with thickend ganache, just to make sure that I wouldn't lose any of the dulce de leche. It does not have to be refrigerated. I hope this helps.

I have used ganache with a buttercream filling - it set very firmly - no bumps or bulges to be seen under the fondant - not sure what Dulce Deleche is so can't comment on leaving it out

Nestle's makes a Dulce de Leche syrup that I mix with my regular non-dairy buttercream. Makes a creamy caramel flavored filling that sits out just fine.

Thank everyone for the info, I appreciate the help!