Posted by megpiThis recipe took a bit of trial and error working, so it's kind of my baby, but I don't mind sharing. It's all butter and holds very well, but I make mine a touch salty to contrast the sweet, so depending on your taste you might want to cut back on the salt. Part of the recipe is by weight, but I've had good luck with the conversion chart at http://www.kingarthurflour.com/recipes2008/master-weight-chart.html
- 12 oz unsalted butter, softened 1lb 6oz Powdered sugar 1/2 tsp vanilla 3/4 tsp salt 2 oz cream
-Cream the butter on high until fluffy -Lower the speed and add the powdered sugar and salt in 3 parts until incorporated -Beat on high until fluffy -Add vanilla and cream until well incorporated. My secret to making it so smooth is leaving it at room temp for a day or 2 (it won't go bad) then mixing it again on low just until the bubbles are all gone, and the frosting is very smooth.