Salted egg yolk croissants might have been hot a few weeks ago, but the pastry of the moment in Singapore is the baked cheese tart, filled with warm cream cheese.

Over the past two weeks, three home-grown bakeries have launched their versions of the tart, together with multiple flavour permutations that range from matcha to salted caramel to tiramisu.

Prima Deli and The Icing Room launched their cheese tarts on April 8. Last week, French patisserie Antoinette started selling them in five flavours, such as grand gru chocolate and matcha.

The tarts have been selling so well that bakeries recommend customers pre-order them.

Prima Deli sells more than 7,000 of its lava cheese tarts across its 40 outlets daily. The Icing Room, with branches in nex mall and Jurong Point, has sold more than 10,000 tarts over the past two weeks. Antoinette sold 250 tarts in the first two days of launching them.

This comes with news that popular Japanese cheese tart bakery, Bake, will open its first outlet here on Friday at Ion Orchard. The 319 sq ft takeaway shop will be the chain's biggest overseas outlet and its flagship store in South-east Asia.

Another big name in Japan, Pablo, which is from Osaka and famed for its large cheese tarts with a gooey core, will also be opening here, although the date and location have not been confirmed.

Baked cheese tarts were made popular by bakeries in Japan such as Bake and Pablo. They have since expanded across Asia, sparking long queues in cities such as Bangkok, Hong Kong and Seoul.

Cheese tarts are not new here, as Japanese bakeries such as Patisserie Glace, which has five outlets in malls such as Icon Village, and Flor Patisserie, which has four outlets including in Siglap Drive, have been offering chilled versions here for more than five years.

Mr Lewis Cheng, 45, executive director of Prima Limited, says its team noticed the cheese tart craze in Hong Kong, which started in August last year, when Bake opened an outlet there. The team started working in its version in January this year.

He says: "With salted egg yolk croissants and cheese tarts trending in the region, we decided to marry the two products, given that cheese and salted egg yolk are compatible in taste and texture."

Demand for the lava cheese tarts is two to three times more than what Prima Deli can produce and the chain has run low on some key ingredients. To deal with this, the bakery has been rationing its distribution of tarts to outlets and looking into air-freighting some of the ingredients from Europe.

At The Icing Room, which is run by the BreadTalk group, response to its cheese tarts has been "overwhelming", with two to three batches sold out within two hours every day. A BreadTalk spokesman says the cheese tarts are an extension of its tart series, launched in August 2014 at its Toast Box chain.

The tarts include golden lava egg tarts filled with salted egg yolk custard and coconut egg tarts. He says: "We started developing baked cheese tarts early last year as cheesecakes. Cheese-related products are loved as desserts by diners here."

Besides Italian mascarpone cheese, The Icing Room uses cream cheese from New Zealand as it has a "refreshing sour tanginess" and fresh Hokkaido milk in its filling.

To stand out from the rest, Antoinette uses puff pastry instead of shortcrust or cookie-based pastry for the tart shell. Chef-owner Pang Kok Keong, 40, uses a reverse lamination method, in which butter is wrapped around the dough to create a flakier texture when baked. He says: "I want to focus on creating a contrast between having a crispy shell and a creamy filling."

The filling is made with cream and mascarpone cheeses.

Despite competition heating up, Bake's president and chief executive, Mr Shintaro Naganuma, 30, is not worried. He says: "It is difficult to replicate the richness and softness of our mousse as our cheeses come from Hokkaido and the secret in creating a light mousse lies in mixing the cream cheese and eggs by hand."

His tarts are filled with mousse made with three types of cream cheese - two from Hokkaido and one from France - and the cookie pastry is baked twice.

Bake sold 10 million tarts in Japan last year. It will open new outlets in Taiwan and Shanghai in June.

Despite having a hit product, Mr Naganuma says the recipe changes every six months. His team plans to make the cheese flavour stronger and ensure that the pastry remains crisp in Singapore's humid climate.

Customers are lapping it all up. Undergraduate Shermaine Lau, 24, is keen to relive her "heavenly experience" of trying Bake's cheese tarts here after she had them in Tokyo last year. "The cheese mousse was so light and airy, it felt like biting into cheese-flavoured snow."

Personal assistant Hazel Lam, 31, says her interest in salted egg yolk croissants spilled over to cheese tarts with salted egg yolk filling from The Icing Room. "I prefer baked cheese tarts to chilled ones as the cheese filling is melt-in-the-mouth. I cannot stop having them."