“What kind of key do you have to cook before using?”/“A latke.”

Latkes (sometimes pronounced LATT-keys) are potato cakes traditionally served on the Jewish holiday of Hanukkah. There’s a latke pun:
 
Q: What kind of key do you have to cook before using?
A: A latke.
   
The joke has been cited in print since at least 2004.
 
   
Wiktionary: latke
Pronunciation
IPA(key): /ˈlɑːt.ki/, /ˈlɑːt.kə/
Noun
latke ‎(plural latkes)
1. A pancake fried in oil, usually made from potatoes and sometimes also onions, traditionally served on Hanukkah.
 
Google Groups: alt.humor.puns
Kids Puns of the Weak 12-07-04
Stan Kegel
12/7/04
(...)
What kind of key do you have to cook?
A Laitke.  (Syman Hirsch)
 
Google Groups: Sailor’s Clean Humor
Thursday a.m. Clean
stewburner
12/25/08
(...)
What kind of key do you have to cook?
A Laitke.
   
The Weekly Post (Portola Valley School District)
December 14, 2009
Pg. 10:
What kind of key do you have to cook before using?
A latke.
 
Twitter
Todd Fritz
‏@brooklynfritzy
What kind of keys open locks on Chanukah?...Latkes (I gave it a shot, as you were) @dpshow
1:57 PM - 9 Dec 2011
 
Twitter
ricks99
‏@ricks99
What kind of key do you have to cook before using?
A ∗lat-key∗! 😊
Happy Hanukkah, y’all!
3:00 PM - 18 Dec 2014