“What is Frosty’s favorite dinner?”/“Spaghetti and snowballs.”

The dish of spaghetti and meatballs sometimes becomes “spaghetti and snowballs” in winter months. “ICED SPAGHETTI AND SNOWBALLS AGAIN?” was published in the Li’l Abner comic strip in 1969.
   
A riddle was posted on Twitter on December 28, 2009:
 
Q: What is Frosty’s favorite dinner?
A: Spaghetti and snowballs.
 
             
Wikipedia: Frosty the Snowman
“Frosty the Snowman” (or “Frosty the Snow Man”) is a popular Christmas song written by Walter “Jack” Rollins and Steve Nelson, and first recorded by Gene Autry and the Cass County Boys in 1950. It was written after the success of Autry’s recording of “Rudolph the Red-Nosed Reindeer” the previous year; Rollins and Nelson shipped the new song to Autry, who recorded “Frosty” in search of another seasonal hit. Like “Rudolph”, “Frosty” was subsequently adapted to other media including a popular television special by Rankin/Bass Productions (formerly known as Videocraft International), Frosty the Snowman.
   
15 March 1969, Tucson (AZ) Daily Citizen, “Li’l Abner” comic by Al Capp:
ICED SPAGHETTI AND SNOWBALLS AGAIN?
 
March 1999, School Library Journal, pg. 164:
BLISS, Corinne Demas. Snow Day. illus. by Nancy Poydar. 47p. (Step into Reading Series). CIP. Random. 1998. PLB $11.99. ISBN 0-679-98222-1; pap. $3.99. ISBN 0-679-88222-7. LC 45810.
Because of a snow day, Emily has extra time to decide on a topic for her school report. She invites her new friend from California over to play, and Marietta suggests that they make a snow town to prevent the neighborhood boys from throwing snowballs at them. In this easy reader set in 18-point type, Bliss uses short sentence structure and repetition to describe the classmates as they make a snow fort, snow town, snow money, and even a snow restaurant with spaghetti and snowballs
 
Google Books
Dogs of a Different Collar
By Marti Regan
Victoria, BC: Trafford
2007
Pg. 70:
“Can I build a snowman now? He can join us for lunch. He can eat spaghetti and snowballs, right? Get it? Instead of spaghetti and meatballs snowballs. Ha, ha!”
 
Twitter
John Pohlson‏
@HotStuffJohn
Q: What is Frosty’s favorite dinner?
A: Spaghetti and snowballs.
1:41 PM - 28 Dec 2009
 
Twitter
Heather‏
@NickysMommy1122
Replying to @ftw_mike
@ftw_mike What do snowmen eat for dinner? Spaghetti and snowballs… #childhumor
10:29 AM - 19 May 2013
 
Twitter
glow$$$$‏
@glowdurley
what do snowman eat
spaghetti and snowballs
12:15 PM - 4 Dec 2014
 
Twitter
Jack Callaghan PS‏
@JackCallaghanPS
Riddles are a great way for students to “play with words.”  Who knew a snow person eats spaghetti and snowballs? Or is it “snow peas?”
6:57 PM - 9 Dec 2014
 
MzTeachuh
Tuesday, November 28, 2017
Cheesy Jokes and Serious Thoughts for Christmas
(...)
What is Frosty’s favorite dinner?
Spaghetti and snowballs.