When you first make Royal Icing, as I did to pipe decorative white lines on my brown gingerbread Christmas cookies, it has a fluffy texture that can do several things. It can be piped into lines and shapes; it can be colored; it can be used as glue for the pieces of your Gingerbread House.
But if you use Royal Icing as pastry glue, you will notice its most important characteristic: it hardens into a brittle form and is no longer pliable. For this reason you don't use Royal Icing as a frosting, as in frosting a cake.
A clear example, I think, is to remember the little penny candies that are sold in some stores: remember the strips of paper that had colored dots stuck to them? You licked the back of the paper and the dots dissolved off so that you could eat them. Yes! Those dots were made of a form of Royal Icing.
So if you want to make a cake or cupcakes that will be frosted with a fluffy marshmallow-type of icing, you don't want Royal Icing. You do not even need Royal Icing mix. Here is how you make Fluffy Frosting.
This recipe does require an electric mixer, hopefully fitted with a whisk attachment. There is simply no comparison between using an electric mixer and trying to whisk this frosting up by hand. In fact, the chances are you will give up and waste ingredients. So even if you own nothing other than a hand mixer, this frosting will work for your Fairy Cakes and other delicate creations.
FLUFFY MARSHMALLOW FROSTING
1-1/2 cups sugar (bakers' superfine is best)
1/2 teaspoon cream of tartar
1/2 teaspoon salt
1/2 cup water
1-1/2 Tablespoons light corn syrup
2 large egg whites, at room temperature
Food coloring and/or colored sugar for decoration, if desired
Put the sugar, cream of tartar, salt, water and corn syrup in a saucepan. Cook, stirring, over medium heat until the sugar has dissolved completely and the mixture forms a syrup.
Place the egg whites in your mixer bowl with the wire whip. Whip on high speed about 45 seconds, until the whites begin to hold their shape.
Slowly pour the syrup in a very thin stream into the egg whites (you can see why a stand mixer would work best here). After all the syrup has been added, whip about 1-1/2 minutes longer.
Add the vanilla and food coloring if you are tinting the frosting, and whip 5 minutes longer, until the frosting stands in stiff peaks and has lost its gloss. Frost your cake immediately.
As you can see, this recipe is a minor foray into candy-making. If you are familiar with fudge, this is similar to the method used to make Divinity, which I used to make until I did it wrong and the fudge turned out soupy.
I shop for baking ingredients such as superfine sugar and cream of tartar at Sprouts in Tucson, but they are available in most larger supermarkets. As I recently found out, you can't always find odd items like chutney at Walmart in Tucson, so go looking when you shop--cruising by some of your standby aisles even if you aren't going to buy things off those particular shelves--just so you know where to go for what.
Tinting this frosting a very light blue will contribute to the Fairy Cake ambience, and you could also sprinkle the cupcakes with pastel sugars for the same effect another way.
1-1/2 teaspoons vanilla extract