So I asked this very question to my coworkers today, and I got about the same result. I decided to have a little fun with dialogue, so it's up to you to guess who the people are that are speaking. Rest assured, it's definitely four (and later five) members of the BAU!
Disclaimer: Criminal Minds is not mine.
"Pie or cake?"
"Huh?"
"It's a simple question—pie, or cake?"
"As opposed to…?"
"Look. Let's say I tell you there's dessert, and you have a choice—a piece of pie, or a piece of cake. Which one would you pick?"
"Depends."
"On what?"
"Well, what kind of cake is it?"
"Does it really matter?"
"Behold the genius at work. Yes, beautiful, it so very much does."
"Why does it matter?"
"Hey, kid, it's simple. Would you eat carrot cake?"
"No—wait a minute, vegetables as cake?! You-you're kidding, right?"
"You've really never heard of carrot cake?"
"It's really made of…carrots?"
"Uh-huh."
"Yup."
"Sure is."
"Huh. Well, that's one cake I won't be eating…"
"So, pie, huh sugar?"
"Yes, pie for me. One without vegetables. Like apple pie…"
"Mmm."
"Oooh! With whipped cream?"
"And ice cream."
"Bean-speck vanilla?"
"What?"
"Yeah, vanilla comes from beans—they put 'em right in the ice cream itself…"
"Wait—they put actual beans in the ice cream?"
"Pretty boy, when was the last time you actually bought a carton of ice cream?"
"It comes in cartons?"
"Oh, my dear lord. That's it. We are so going for dessert now."
"Well, make it five minutes? We'll have to sneak out if we don't want to get caught…"
"What, by who? Like anyone cares if we go for pie."
"Not what I was thinking…"
"Hey, great, I found you all. There's a new case, looks pretty bad. And did I hear someone say pie?"
Four heads shook themselves as they trudged towards the round-table room, thinking only of the pie they were missing.
Points if you can figure out who was going for dessert...