My friend makes the best frosting but she will not share her recipe. We have been friends for over 30 years, but she will not share any of her cookie recipes because they are old family recipes. (When my daughter started teaching my friend and her husband made cut out sugar cookies and frosting, took them to her class so the kids could frost their own cookies. She thought it was sad so many kids didn't get the experience. And the kids loved it.)
I have bought the frosting the bakery in our grocery store sells after my attempts never quite turned out the way I liked.