Twelve years after Sept. 11, 2001, the way we remember the terrorist attacks has fallen into predictable patterns. In the United States, we mourn. On certain jihadist message boards, blogs and social media pages, people celebrate.

This year was no different. The Middle East Media Research Institute, a think tank that monitors extremist social media, rounded up dozens of pro-9/11 tweets, Facebook posts and forum threads from across Africa and the Middle East. The posts can be both grim and upsetting, but they’re also important -- as MEMRI notes, the anniversary of attacks on the United States can play into propaganda  for al-Qaeda and its ilk. You’ll recall that Inspire, al-Qaeda’s English-language magazine, dedicated an entire issue to the Boston bombings in May.

For the most part, those messages are just what you’d expect: eulogies for the Sept. 11 bombers, photos of the attacks and calls for the “glory” to continue. al-Shabab, an al-Qaeda affiliated group active in Somalia, posted several messages in English:

But one photo, posted to the popular Facebook page of a Tunisian Salafi group, stands out: It’s a Sept. 11 cake, complete with an outline of Osama bin Laden’s face, a model plane, and “Happy 911” candles. The superimposed text, according to MEMRI, reads: “Woe to America and its people / I could almost see Al-Qaeda getting prepared / For a day similar to that Tuesday when / We spilled the disbelievers’ blood.” This is not, apparently, the only cake in this genre -- a photo circulating on Twitter, hashtagged with the names of several Middle Eastern countries, shows a similar creation.

Extremists did not actually bake these cakes themselves this week -- the photos have been online for several years, and it's not clear that English-language letter candles would be widely available in Tunisia. But the popularity of the images, and the glee with which they’ve been spread, seems to speak to a level of directionless hatred that terrorism analyst J.M. Berger addressed in a fascinating "open letter to jihadis" on Wednesday.

Most extremists, Berger argues, are well-meaning (if horrifically misguided) people who want to better the lot of Muslims around the world. But to achieve that goal, they turn to al-Qaeda -- which preaches senseless killing that undermines their own mission. To quote Berger:

Al Qaeda’s ideas guide your movement, and the philosophy of Al Qaeda (unlike that of Islam) is based entirely on destruction … Win, lose, help people, hurt people, it’s all the same to Al Qaeda.

‘As long as there is slaughtering, we're with them. If there's no slaughtering, there's none, that's it. Buzz off,’ as one member of your movement put it, in an unguarded moment. The only real constant is death.

That argument is not only unreligious, it’s insane. It causes you to pursue killing instead of building a stable foundation for your beliefs and your community.

Fortunately, Berger says, he’s noticed that online extremists are increasingly “uncomfortable with terrorism,” particularly when it targets civilians. They have begun to discuss more “moral” -- presumably, less violent and less hateful -- ways to reach their goals.

Does that mean we’ll see fewer Sept. 11 cakes next year? Probably not. But we can hope that, eventually, the tone turns a little less gleeful.