I plan to do all the assembly on this cake tonight and have it finished when I go to bed. I'm taking it to a party at noon, which I will be attending. Is it fine to leave it out all night uncovered? I really wouldn't know how to cover this once its assembled, so all I could think of was to leave it out. (?)

My cakes just sit out on the counter, sometimes for a couple of days.

I was just talking to the friend (who the cake is for) and she was asking if the cake would get hard since it was being left out. She suggested toothpicks and plastic wrap, but I don't want all those toothpick marks on the cake!

So, I can tell her its fine then... ?

Geesh, these poor cake civilians! They'll leave store bought doughnuts in their pantry for a week, but omg let's not leave a cake sit for a few hours!

The "cake" won't get hard. If you used a crusting icing, the icing will be crusted, but the underside of the icing should still be nice and soft. I mean the icing won't turn into a life saver candy hardness or anything!

yes, it will be just fine. I leave all my cakes out over night

If a cake is covered with crusting buttercream (as indybedi mentioned) or fondant -they should be fine on counter. I have left mine out on counter for as long as two days and nights. Once cut, I was told that it was moist and yummy and could I do a wedding cake for sister in law?

Will it fit in your oven? That's where I keep my cakes when I have several to store overnight. I've even kept them in my car (I have a hatch back) on nights it's really cold. I always worry that someone will bump them or my son will decide to sneak a taste (he's done it before) if he wakes up before I do.

Just remember to put a note on your oven so you don't forget and turn it on in the morning.

Well any cream cheese or whipped cream fillings?
Don't leave those out.

Don't put it in the oven if you have a pilot light.

Don't leave it out if you have any pets. Cats will eat cake and sit in your cake boxes.

OK to leae out unless it has perishable fillings... But I would find a way to cover it to keep dust, hair, etc out of it...

Wow!!! Thank you so much! No pets, but I do have a 3 year old and being a candy cake, I'm thinking he might sneak a bite
Its a crusting buttercream, no fillings. It would be too tall to fit in my oven, but the car might be a good idea.
It has to go there anyway... Better sooner than later.
Thanks! I can try to conceal it from dust and what-not, but my main concern was any hardness to the cake or icing... I thought it would be fine!

If your worried just use some tissue paper to cover it up.