You can use wow butter or any other spreadable food item.
It might be fun to use a spread that students may not be familiar with and let them try it out afterward. (e.g. vegemite, nutella, spam, leberwurst)
I've done the PB and J activity in biology class to demonstrate genetic mutations--so I'd probably change things up so that students would see something new. Ask them to give instructions on how to load a printer or replace a cartridge.
@swood I'm curious to know if many of your students knew how to change a printer cartridge? This sounds like an interesting switch up.
I as well as my students loved the activity where students had to write out directions on how to make a peanut butter and jelly sandwich. I then pulled in other teachers to follow each set of directions. It was fun. It was enlightening for the kids. Immediately, they wanted to go back and "fix" their instructions once they made the "connection" about what I was trying to show and teach them.
I would use frosting or some sort of fruit jelly.
Nutella is really big at my school. I would substitute that.