The Annual Birthday Cake Fight

It's worse than the back labour was many moons ago, though not as bad as the hospital trip the following week. And every year it returns: the revenge of the cake.

I'm fighting today, again, as I do every year, with my son's birthday cake. This year it's Hogwarts castle.

Now, I could just use pre-made frosting, or use a rolled fondant recipe. But--there's always a but--I refuse to feed my kids and their friends hydrogenated fats, large amounts of corn syrup, and wish to avoid gelatin (as we are vegetarians)and raw eggs (because salmonella isn't a nice fella). I know that cakes aren't notoriously healthy things to eat, but there is junk food and then there is slow acting poison. I'd prefer to avoid the latter.

This severely limits what one can do in terms of icing.

In the past I have made a poured fondant recipe found on the Wilton site with mixed results. It has a nice finish, but does tend to run somewhat before hardening. And it uses corn syrup.
Another trick that has worked is to melt chocolate chips and add butter and milk. Unfortunately, that won't work here as I don't want it to "crack".
This year I tried the royal icing mix from the Bulk Barn. It kept running off the cake, not because it was watery (I used less water than they called for and it was very thick) but because it wouldn't set. There are no fats in it to hold its shape I guess. Seems like a familiar conclusion--I think I've done this before. Perhaps I should write it down somewhere so I remember next time!

I was hoping to use a rolled fondant, but cannot find any powdered agar for it.

I did have some success though with the cupcake icing. This uses cream cheese and butter as a base. So once all of the royal icing (expensive mix too!) flows off the cake, I will make a batch of that and start over.

The recipe is in "Super Baby Food" which is an excellent resource for all ages of people who eat (but maybe not so much infants and toddlers as it assumes breastfeeding ends a few weeks after birth).

Here it is:
3/4 package cream cheese, softened
4 tablespoons softened butter
1 teaspoon vanilla
4 cups icing sugar

All you do is cream the 1st 3 together then slowly add the icing sugar. Simple, yummy, and it works like you would expect a cake icing to work (like a butter cream icing I would imagine).

Like with the paper mache, and now with the icing, I hope that through my own failures, I can help others to attain success.
Enjoy!