In searching for my Prosser ancestors I ran across this in Heritage Quest - a book with will abstracts.Certain this is what you are looking for.
Abstracts of wills of Dutchess County, New York.Minnie Cohen.New York: unkn, 1939.901pgs. Vol VII. (years 1814-1818) page 16 "Page 123. "BENJAMIN PROSSER, Pawlings "Dated October 28, 1815; probated February 5, 1816. "Mentions:wife Rachel and sons Icabod (Ichabod), Lyman "Executors:friends Lewis Stebbins and Samuel Stebbins "daughter Charlotte Wiant "Witnesses:Simeon Clinton and Lewis Stebbins, Jr. and Samule Stebbins, Jr. "Signed:Benjamin Prosser"
The other Prosser name is a married daughter of Solomon Beach. Vol XIII (years Oct 1834 to Oct 1839) page 27 "p.258Solomon Beach of Pawling. "Dated:May 22, 1823 "Probated:June 20, 1836 "Mentions:wife Hannah - dau Thankful Davis - dau Phebe Prosser -son Clerk Beach "Executor:Clerk Beach "Witnesses:Newel Dodge Jr - Sarah Dodge - Ann Dodge"