It was 3 February when the queues started forming at Boulangerie Louvard in Paris. Even in the sort of downpour that usually empties streets, clued-up teenagers gathered outside the family-run bakery in the 9th arrondissement, desperate to get their hands on one thing: its owner Stéphane Louvard’s invention, le crookie. It’s a crisp croissant filled with American-style cookie dough, then baked to achieve a soft, gooey centre, and a video of the Frankensteined pastry had gone viral on TikTok. Arriving a decade after the New York-based French pastry chef Dominique Ansel revealed the recipe for his cronut, the crookie is the latest in a long line of hybrid croissant offerings to cause international fervour. “We were very surprised,” says Louvard, who now sells up to 2,200 crookies per day. “We had to hire two additional people to be able to produce the necessary quantities. It was a little stressful.” Bakeries across Paris have now started selling them. “My local is doing it, even though it’s not very trendy at all,” says Houssine Bouchama, director of Time Out Paris. Meanwhile, from Singapore to Toronto, copycats are making their own versions. Cookie Crumble, a micro-bakery in London, has been getting orders from across the country. Rhiain Gordon, founder of Babyfaced Baker in Edinburgh tells me it’s “unusual to see any left by 10am”. To say that cross-bred takes on classic breakfast pastries have captured public imagination is an understatement. In 2013, when Ansel first brought the cronut, with its glazed doughnut outside and flaky pastry inside, to New York, they sold out so quickly that a black market arose on advertising website Craigslist. By the time it landed in the UK in 2016, it was with so much fanfare that Londoners skipped work to try it. A muffin-croissant hybrid, the cruffin, was next, causing such a stir at Mr. Holmes Bakehouse in San Francisco that in 2015 the recipe was reportedly stolen. Then came the croloaf (croissant dough baked in a bread tin, debuted by M&S in 2016). There have been tacros (pulled pork filled taco-shaped croissants created by San Francisco’s Vive La Tarte) and cretzels (salted pretzels made with croissant dough, by Seattle’s Coyle’s Bakeshop). Since the global launch of TikTok in 2017, the appetite for these hybrid snacks has accelerated. In 2022, the suprême – a spiral of croissant dough stuffed with the pastry creme-filling of an Italian bomboloni doughnut – became a global sensation. Next came the croffle; croissant dough pressed in a waffle machine, popularised in South Korea by cafe chain Aufglet. What is it about hybrid croissants that have captured global public imagination for so long? Meg Palmer, a research manager at market research agency Verve, thinks it’s because “there’s something about the merging that makes it more permissible to be indulgent”. Pastries are also perfect for TikTok, she explains, because they look and sound great. “[In videos of] the crookie you see hands breaking through the croissant. You hear that initial crunch, and you see whether it’s got filling if it oozes out. It’s very sensorial.” She ties the constant invention of hybrids to small businesses trying to stand out on social media. “They’re always thinking ‘what can be our hook?’ People do latch on to these trends, and they don’t just want a flat white and a croissant any more.” Bouchama has seen the impact of this in Paris. “There’s an Americanisation of French patisserie going on; the desire to reach an international audience on TikTok,” he says. Bakery Philippe Conticini in Islington is London’s main purveyor of novelty croissants. The chain launched in London in 2020 with classic French patisserie, but found it hard to survive. “We’ve found we have to be creative all the time and follow the trends,” says Ludovic Carassi Del Villar, operations manager. The shop soft-launched its £5.90 crookie last week and is already getting calls demanding more. Back in Paris, TikTokers are already moving on, says Bouchama: “Some bakeries are now experimenting with the pain au chocolat-brownie.”