After the last batch, I had several requests for the icing recipe, so I made careful notes this time.
Enough for 2 dozen cupcakes iced with a spatula, or one dozen piped.
1/2 lb powdered sugar
1 stick softened butter
1 teaspoon milk
1 teaspoon vanilla extract
1 teaspoon spiced rum
food coloring (keep in mind that the icing will start off slightly yellow from the butter when choosing a color)
(I was amused to see that the alcohol content on the rum was actually less than that of the vanilla extract, but I suppose you could use rum flavoring if it's an issue for you)
Microwave the bowl of powdered sugar for 30 seconds. It sounds kind of weird, but since the frosting itself isn't cooked, microwaving the sugar on its own will get rid of that weird metallic taste the corn starch in the powdered sugar sometimes has. Add all other ingredients and mix well. If the icing seems a bit too stiff, add milk in small amounts until it reaches the right consistency.
I like to let the icing rest in the fridge for a bit if I'm going to be piping it, as my hands are very warm and otherwise I can only do about 3-4 cupcakes at a time before I melt the icing too much to get any real definition.