cream Look up cream at Dictionary.com
early 14c., from O.Fr. cresme, blend of L.L. chrisma "ointment" (from Gk. chrisma "unguent"), and L.L. cramum "cream," perhaps from Gaulish. Replaced O.E. ream. Re-borrowed from Fr. 19c., as creme. Figurative sense of "most excellent element or part" is from 1580s. Verb meaning "to beat, thrash, wreck" is 1929, U.S. colloquial. Related: Creamy (c.1600). Cream-cheese is from 1580s. Creampuff, in fig. sense of "weakling, sissy" is recorded from 1930s.
"I remember my first campaign. My opponent called me a cream puff. That's what he said. Well, I rushed out and got the baker's union to endorse me." [Sen. Claiborne Pell, D-R.I., 1987]
As a salesman's word, "something that is a tremendous bargain," it is from 1940s.