I'm going to bake a birthday cake tomorrow and I want to make my own frosting for it. I looked online for recipes and was a little overwhelmed by the variety -- some use granulated sugar, others use confectioner's sugar; some use eggs, others use butter or shortening. I'm not sure if I want to use eggs as an ingredient in something that won't be cooked to kill any salmonella. Also, something that I can make in advance and keep in the fridge overnight would be great. Any suggestions?