2017 Apple Butter Makin' Days will be held on October 13th thru October 15th. Apple Butter Makin' Days, one of Missouri's most popular festivals, has been held on the courthouse square in Mt. Vernon each October since 1967. The main attraction is apple butter, cooked using century-old methods in huge copper kettles over open fires. That craft is demonstrated on the southeast corner of the courthouse lawn starting shortly after dawn and continuing until early to mid-afternoon each day of the festival.