“What’s a math teacher’s favorite dessert?”/“Pi.”

A math riddle is:
 
Q: What’s a math teacher’s favorite dessert?
A: Pi(e).
 
The joke has been cited in print since at least 2008 and has been printed on several images.
     
   
Yahoo! Answers (September 10, 2008)
Some funny puns for class? ?
Best Answer:
(...)
What is a math teacher’s favorite dessert? Apple pi
wow_bill
   
Kid Activities
School Jokes & Computer Jokes
June 29, 2009 23:05 by Barbara Shelby
(...)
Q. What is a math teacher’s favorite dessert?
A. Pi!
   
Twitter
Fozzie Bear‏
@Fozzie_Bear
Q. What is a math teacher’s favorite dessert? A. Pi!
8:21 PM - 21 Aug 2009
 
Google Books
Laugh-Out-Loud Jokes for Kids
By Rob Elliott
Grand Rapids, MI: Revell
2010
Pg. 46:
Q: What was the math teacher’s favorite dessert?
A: Pi.
 
Twitter
Math Monkey‏
@MathMonkeySolon
What is a math teacher’s favorite dessert?
Pi!!!!!
1:12 PM - 28 Sep 2010
     
Google Books
December 2012, Boys’ Life, “Think & Grin,” pg. 64, col. 1:
Max: What is the math teacher’s favorite dessert?
Miles: What?
Max: Pi.
Max Stewart, Tacoma, Wash.
 
10 August 2013, Newsday (Long Island, NY), “Smiles,” Kidsday, pg. B28:
What is a math teacher’s favorite dessert?
Pi.
- Jack Maccarone
 
B2C (Business 2 Community)
20 Pi Puns to Inspire Your Nerdiness
Grammarly — March 14, 2016
(...)
11. What is a math teacher’s favorite dessert? Pi!
 
Google Groups: alt.fun.with.tob
Humor from the Net
Bill McCray
3/14/16
(...)
What is a math teacher’s favorite dessert?
Pi!
 
Reddit—Jokes
What is a math teacher’s favorite dessert?
submitted March 15, 2016 by kimkawe
Pi(e)