I wanted to make some cupcakes with creamcheese frosting and jam filling then covered with fondant- are either of these going to spoil if unfridged for a day?

If you google: Sturdy Whipped Cream Frosting you will find in allrecipes website. This yummy creamcheese frosting that can be left at room temperature for 24 hours.
I have been using this a lot, even as filling for wedding cakes, and it works, is creamcheese/whipcream, it tastes really good.

I personally omit the almond extract.

Just make sure the bowl and paddle have been in the refrigerator for a couple of hours, so you get a very good consistency on it. Otherwise it will be too runny.

Good luck!

I find it interesting that the Sturdy Whipped Cream frosting info says
it's very stable and can be left at room temperature..and it makes a great dip:

http://allrecipes.com/Recipe/Sturdy-Whipped-Cream-Frosting/Detail.aspx

The Whipped Cream frosting in the CC recipes section uses more sugar and less whipping cream to the same amount of cream cheese and it's not shelf stable:

http://cakecentral.com/recipes/901/whipped-cream-frosting

One of the biggest complaints (for both recipes) is that the recipe sometimes doesn't seem to work at all, leaving you with "dip" instead of frosting.

But my issue with the "Sturdy" recipe concerns safe food handling practices... I cannot understand how this recipe is shelf stable. And for the poster on allrecipes to simply say "can be left at room temperature) without any qualifiers seems irresponsible.

To save time later, I always make my frosting while my cakes bake. Can I use this frosting on a 3 tiered cake (too big for my 'fridge) that takes 2-3 days to bake, freeze, assemble and decorate without worrying? I don't think so.

I don't know this woman(no disrespect meant) but she's obviously not a well known baker/decorator/someone who has shared a recipe that was tested by food scientists for shelf stability (or she'd certainly say so).

Food poisoning is a terrible thing. I experienced it once, and I have no wish to do so ever again. I'm sure this recipe would be fine without refrigeration - but only for four hours (at a time).

The truth about cream cheese frosting:
(Many links to previous threads on food safety, difficulty in decorating, shelf stable recipes, etc.)

http://cakecentral.com/cake-decorating-ftopict-615264-.html

Cream cheese frosting and fondant:

http://www.cakecentral.com/cake-decorating-ftopicp-6620931.html#6620931

HTH