buttercream

Etymology

butter +‎ cream

Noun

buttercream (plural buttercreams)

1. (cooking) A type of thick, sweet icing or cake-filling made by creaming butter (or sometimes another fat, such as margarine) with powdered sugar.
   • 2009, January 9, “Basil Katz”, in Gaston Lenôtre, Who Built a Culinary Brand, Is Dead at 88‎:

     He was the first one to use gelatin in his buttercreams, and to make such extensive use of the freezer.