I need a shelf stable filling for a RV cake. It will be sitting out for 4 days while it's being made. How do you feel about regular vanilla buttercream frosting? Any other ideas?
Re: "It will be sitting out for 4 days while it's being made."
If you plan on eating it, I don't recommend leaving it sitting out (unrefrigerated) for 4 days.
Re: "...vanilla buttercream frosting"
Buttercream frosting can be stored at room temperature for up to 6 hours, after that it needs to be refrigerated (up to 1 week) or frozen (up to 8 months).
You can find a stable vanilla buttercream recipe at the link below. But, the storage requirements is as stated above. The stability of this buttercream is that it can hold up in warmer climates and it is firm enough to use to pipe decorations on a cake.
Many people use a Mary Kay icing (don't know how it got that name) on Red Velvet cake. Here is a version: http://www.cakecentral.com/cake_recipe-7376-0-Mary-Kay-Icing.html Hope the link works. If not just search for "Mary Kay". Sitting out for 4 days may push it over the edge, however.