In 1771, King Adolf Fredrik finished off a casual meal consisting of fish, Russian caviar, lobster, boiled meat and turnips with some semlor. But he wasn't satisfied with one or two - according to legend he devoured 14 - and died as a result.
But for most people one or two are plenty enough.
The renowned Tösse bakery in the fashionable area of Östermalm in Stockholm has won several awards for its Semlor. So what is the secret behind the success?
According to pastry chef and owner Mattias Ljungberg it all has to do with passion - and love.
"It is so many small things that make up a good semla, but you have to love the product," Ljungberg says. "It doesn't matter how many times I show my employees how to make a semla - if they don't like to make them the result won't be good either."
Behind the scenes at the bakery there is a whole team of bakers churning out semlor by the thousands. And this year they are hoping to break the record - the aim is 8000 semlor.
But the days when Swede's only ate semlor on "fettisdagen" or Fat Tuesday are long gone - nowadays Swedes start eating them most of the winter. But some of the customers Radio Sweden spoke to keep the tradition.
"I just eat semlor today, actually," , the self-proclaimed traditionalist Lotta Drake says.
The tradition of eating them with whipped cream and almond paste dates back to the turn of the previous century. And that basic format has stuck - even if some try to reinvent it every year, adding blueberries, strawberries, saffron and other even more unusual ingredients.
For some of the punters at Tösse, such experiments are an abomination.
"I don't like it," Lotta Drake says just before it's her turn to buy the precious buns.