Co-written and first recorded by Charlie Phillips (1957).
Hit versions by The McGuire Sisters (US #1/UK #14 1957), Johnny Cash (C&W #13 1961).
From the wiki: “‘Sugartime’ was written by Charlie Phillips and Odis Echols, and was first recorded in 1957 by Phillips with Buddy Holly on guitar. Produced by Norman Petty, it was released (as the B-side to ‘One Faded Rose’) on Petty’s Coral record label.
“The biggest hit version was also recorded in 1957, by the McGuire Sisters who topped the pop music charts with the song in 1958. In 1961, the song briefly returned to the country charts in 1958 with an arrangement Johnny Cash first recorded during his tenure at Sun Records 1955-1958.”
The McGuire Sisters, “Sugartime” (1957):
Johnny Cash, “Sugartime” (1961):