A burglar has stolen the coveted cruffin (pictured) recipe from one of San Francisco’s most well-known bakeries, Mr Holmes Bakehouse.

The bakery, which is co-owned by Melbourne-born Ry Stephen, reported its recipe for a croissant-muffin hybrid had been stolen in March. The thief didn’t stop there, carting away five binders containing more than 200 recipes from the bakery’s kitchen.

The strangest part of the story is the alleged thief left behind several costly items that most burglars seek out, such as an iPad, cash and computers.

Luckily, Ry said he keeps backup files of all store recipes and said it was, “back to business as usual” the following day.

“There is a spirit of learning among pastry chefs. But there are always one or two who are trying to take everything and not give back. That’s the part that disappoints me,” he told The New York Times.

Nonetheless, the French-trained pastry chef and recipe-inventer said the burglars would be in for a rude shock as cruffins take up to three days to make, with the key to success in the technique, not the ingredient list.

In fact, the stolen cruffin recipe doesn’t go into any detail about Mr Holmes Bakehouse’s signature dough-making technique, which involves a lengthy process of mixing, buttering and folding repeatedly, and then baking across a few days.

The business regularly attracts 50-deep lines for its selection of artisanal pastries that includes brioche doughnuts, muffins and mini tarts. News reports of the theft have only drawn more crowds to the popular bakery, according to the NY Times, which now sells out in record time.