Maybe it was the frosting, which a TSA agent tsk-tsked for being "too gel-like."
Or maybe it was the sinister name of the company that baked it -- Wicked Good Cupcakes -- that made the federal agency charged with protecting America's transportation systems suspect the cupcake contained more than chocolatey holiday cheer.
Whatever the reason, we now have the latest TSA scandal: Rebecca Hains, a Peabody, Mass., college professor, says a single cupcake was confiscated by TSA agents in Las Vegas last week.
The agency bans certain liquids and gels, even though there's no convincing evidence that terrorists are plotting to bring down a plane with liquid explosives or specifically that the topping in a single tasty holiday cupcake could incinerate an aircraft.
These must be actions of a single, overzealous TSA agent, right?
If only. When I mentioned this story on Twitter a few days ago, I heard back from readers who said airport screeners were busy confiscating all kinds of Christmas contraband, including snowglobes and cheese dip.
Truth is, the TSA has been swiping our holiday stuff for years.
One of the earliest reports came by way of Jessica Bruder, a writer for the Portland Oregonian who flew to Illinois over the Thanksgiving holiday in 2007 and almost had her apple pie confiscated by a federal screener.
After sliding her dish through the conveyor belt, the interrogation began:
"Are you the pie lady?" the agent demanded.
Standing there in orange polka-dot socks, jeans inching down my hips, I nodded soberly. He indicated we'd have more to talk about on the far side of the metal detector.
When my pie emerged, the questions began.
"What kind of pie is that?" He squinted at the pan.
"Apple. With some raspberries."
"Does it have lumps?"
I glanced at the crust, which was black in places and looked like a topographical rendering of the Himalayas.
You get the idea. The agent eventually let her fly with the pie, but admitted to confiscating dozens of pumpkin pies because they were too close to the consistency of plastic explosives.
Snowglobes are not, however. Why? I haven't heard a reasonable explanation yet. But here's what happened when agents told blogger and Houston Chronicle features editor Kyrie O'Connor she couldn't take hers on the plane earlier this month:
The TSA confiscated my snowglobe.
"Really?" I said. "I bought it at the Lexington airport. I didn't expect to be here. I'm just going to walk down that hall and buy another. Exactly how are you making the world safer by taking my snowglobe?"
And, dear reader, that is when I -- not a crier -- began to cry.
They took my snowglobe.
"Maybe this is the low point of your day and everything gets better from here," said the chirpy TSA woman.
What's going on here?
Does the TSA really believe we're going to commit a terrorist act with a snowglobe or a cupcake? If it does, then it's a lot stupider than it looks in those dashing, law-enforcement style uniforms Congress is allowing its agents to wear.
A far more plausible explanation is that this is just another dark act in TSA's ongoing security theater. It's an episode that repeats itself every Thanksgiving and Christmas, and is intended to remind American air travelers that there will be no peace on earth, no good will to anyone, until the war on terror is won.
Sure, taking away our pies, cupcakes, snowglobes and cheese dip is a relatively minor thing compared with the blatant violations of our civil liberties that take place every day at the airport, including the invasive pat-downs and dangerous body scans.
But it is, on another level, equally troubling.
TSA's actions chip away our holiday cheer, which in recent years has been in short supply. They don't make us feel safer. Instead, they annoy us, sadden us, even demoralize us.
It's like getting a Christmas card from Al-Qaeda.
Thanks for nothing.