This is a great recipe for cake and cupcake decorating. If you want it thinner, just add 3 tablespoons of golden syrup or a little more water to the icing.
As a professional decorator, this icing is a great base. Most will think it too sweet and I agree but you can use 1/2 shortening (hi-ratio or Sweetex is best but crisco will work if that is all you can get) and 1/2 SALTED butter and add 1/4 tsp salt also (popcorn salt works best as the grains are smaller but regular table salt works fine if that is what you have), salt cuts the sweetness in icings! - 23 Apr 2006 (Review from Allrecipes USA and Canada)
This frosting was amazing! I used it to repair a store-bought cake that my mother dropped. It turned out beautiful and tasted great. My husband was teasing me about eating the icing by the spoonful. I used all butter in mine. I suspect that anyone who had a problem with the frosting tasting like shortening probably had shortening that was going bad from age. I learned from experience that if shortening is old, the flavor overpowers anything it's cooked in. Yuck! Anyway, this is definitely my new favorite icing recipe! - 03 Jun 2007 (Review from Allrecipes USA and Canada)
Very easy to make! My version is: I did 1/2 butter 1/2 shorting and only 3 cups of sugar. I also didn't fill the 1/2 cups all the way because I only had 20 cupcakes to frost. I also used 1 TB milk instead of water and added about 2 ts. concentrated defrosted canned OJ and orange marmalade (to taste-about 2 TB) to make an orange flavored frosting. You can even add a drop or 2 of orange food coloring! It turned out great!!! - 05 Nov 2001 (Review from Allrecipes USA and Canada)