“Banana nut bread/muffin” means a bread/muffin with bananas and nuts. “Nut” is not a verb (or a noun meaning a man’s sexual genitalia), but there are jokes.
 
“I didn’t know bananas are nuts, Banana Nut Cheerios. That’s a bunch of lies!” was posted on Twitter by (((Mark Campbell))) on August 24, 2010. “Banana nut bread? I didn’t know bananas had nuts!” was posted on Twitter by Sandia de los muertos on October 12, 2010. “Banana nut bread? I didn’t know bananas could ejaculate” was posted on Reddit—3amjokes on October 23, 2019.
   
     
Twitter
(((Mark Campbell)))
@MrWordsWorth
I didn’t know bananas are nuts, Banana Nut Cheerios. That’s a bunch of lies!
9:35 PM · Aug 24, 2010·ÜberSocialOrig
 
Twitter
Sandia de los muertos
@sammythehouse
Banana nut bread? I didn’t know bananas had nuts!
6:43 PM · Oct 12, 2010·Twitter Web Client
     
Twitter
alyssa ogden
@alyssa_freshhh
*talking about muffins* mom: “David do you like banana nut?” Dad: “I didn’t know bananas had those..” -_-
6:26 PM · Jul 6, 2013·Twitter for Android
 
Twitter
Despachico
@_CHlCO
Banana nut bread muffin? I didn’t know bananas had nuts
12:12 PM · Jul 19, 2014 from Naperville, IL·Twitter for iPhone
 
Twitter
Awake At What Cost
@DannyRavioli
Banana update: Bananas could nut
Resources: Banana nut bread
9:09 PM · Jul 17, 2017·Twitter for Android
   
Twitter
YSASSI 🎃
@omar_vk3
Banana nut muffins are gross I didn’t even know a banana could nut
2:53 PM · Feb 18, 2018·Twitter for iPhone
 
Twitter 
spooky princess🖤💀
@minnsiemouse
Me: hey that looks good! What are you eating?
Friend: oh it’s banana nut bread!
Me: huh.. I didn’t know bananas could do that.
9:10 PM · Dec 19, 2018 from Napa, CA·Twitter for iPhone
 
Twitter
🏳️‍🌈Ðᶓẋƭᶓȓ Ȧʅʅḁḡḁḧṙᶓỉ🏳️‍🌈
@BlueFoxalope
Me : : *orders banana nut bread*
(Pull up to drive through window.)
Rusty : : *to cashier* So… I didn’t know bananas had nuts.
Husband noooooo…. *facepalm* How on Earth have you ever gotten people to date you? 😓
9:06 AM · Jan 14, 2019·Twitter Web Client
 
Twitter
👻
@blaiddydtxt
banana nut bread i didnt know bananas could nut
4:16 PM · Mar 7, 2019·Twitter for Android
 
Reddit—3amjokes
Posted by u/levarela October 23, 2019
Banana nut bread?
I didn’t know bananas could ejaculate