COSS-ANT, "croosont." Those who remember the lady from Texas, the one who thought quiche should be pronounced "qwish," will not shudder as a new wave of Francophiles attempts to pronounce croissant.

They may shudder, though, at what's happened to the plain, buttery, crescent-shaped breakfast bread that seems to be going the way of yogurt. (If plain is good, pina colada flavor must be better.)

But this time you can't blame it entirely on the American penchant for change. Strawberry, chocolate, almond-filled croissants are sweeping Paris. And the craze, which is about to blossom forth in Washington, appears to have made its way both east and west, from Los Amgeles, via Denver and Aspen, Colo., and from across the Atlantic.

In Aspen (year-round population 10,000) there are eight places to buy croissants this winter, including the airport terminal. But then, they sell yogurt from vending machines at the airport, too. Much of the croissant-impetus there comes from the same company that appears to be spearheading anything-goes-croissants here -- Vie de France. The company, which started out making French bread, has a bakery in Denver, too.

"It's the hottest thing going in France," says the manager of the Vie de France restaurant on K Street. "All natural, no preservatives. It's a wholesome food, a new concept.

"People are searching for something different, instead of doughnuts or a hamburger," explains Aspen baker Joe Cucinella, late of Saks-Jandel, where he sold fur coats.

Different, all right. In Los Angeles, a Chinese baker is selling pinwheel-shaped croissants, filling with lemon and cream at Le Croissant on Sunset Boulevard. According to the Los Angeles Times, Henry Lo thinks croissants will replace doughnuts in five or 10 years.

On a recent trip to France another Los Angeles baker was taken with the meteoric rise of a fast bread chain in Paris called La Croissanterie -- so taken that he rushed back home and opened "an exact copy," Croissants U.S.A.

What would the Fracophiles think if they knew that croissants came to the United States from France via Budapest?

Back in 1668, the Turks were digging their way into Budapest through underground passages while the city slept. If it hadn't been for bakers, who work while others sleep, they might have succeeded. The bakers heard the tunneling and warned the city in time to defend itself.

As a reward the bakers were granted the privilege of making a special pastry in memory of the Ottoman flag emblem, a half moon, or crescent.

Those were plain croissants, croissants ordinaires. For years they were good enough. Redolent of yeast and warm sweet butter, they were usually slathered with more butter and served with morning coffee.

The croissant craze of the '80s has spawned something beyond the ordinary croissant, and there is some question whether some of the things they are selling as croissants, really are.

There are croissants filled with blueberry, peach and raspberry jams, apples, apples and walnuts, cream, cheese and honey, cream cheese and raspberry, cream cheese and rum raisin, almond, chocolate, hazelnut, ham, ham and cheese, broccoli, spinich and mushroom, beef, mushroom. Need I go on?

Some of the beef- and the mushroom-filled, look distinctly like turnovers rather than croisssants. Some of them, especially the pain au chocolat, are square. Are they still croissants?

Filling croissants follows in the footsteps of earlier edible containers: croustades, popovers and tacos. Slicing croissants (usually day-old) in half, lengthwise, and making them a substitue for Wonder Bread, follows in the tradition of English-muffin pizzas, which begat French-bread pizzas. There is also a cousinly relationship with cream puffs, quiches and crepes.

The American Cafe has served roast beef, chicken tarragon salad, roast beef-pate-mushroom sasndwiches on croissants since it opened. From time to time, The Bread Oven serves eggs benedict and creamed fish on croissants, and at Les Delices croissant sandwiches come with swiss cheese, brie, ham, ham and cheese or pate.

Les Delices also has plans. Plans for croissants filled with hot dogs, among other things. Two chefs will be arriving from Paris within the month, from a Parisienne operation called Croissant Show (a play on word in France where chaud , which means hot, is pronounced show.) The chefs will prepare the latest in filled croissants.

But French chefs who have been living in the United States for several years are not "into" filled croissasnts. Asked why Watergate Pastry has none of these newfangled croissants, Elizabeth Siber, president of Restaurant Corporation of America, which runs the Watergate restaurants, said: "because our chefs are European."

There are people who think those old-fashioned Europeans are right. Said one American taster when he tried the ham-and-cheese-filled croissant: "What is this, Hardees?" And he continued, innocent of marketing practices that insist on 97 variations of the same product in order to sell more: "The plain are very good. Why don't they understand that and make them plain?"

Says Pastries Francaises: "We don't worry about filling croissants, because they are delicious as they are."

The truth of the matter is, some filled croissants work; others, as one taster noted, are like Tasty Pies.

The chocolate- and almond-filled croissants, at about 60 to 75 cents each, are good for dessert. The ham and cheese, at $1.15 to $1.25, are good for lunch. The fruit-filled, at 80 cents to $1.15, are good for nothing. gThe plain, at 50 to 60 cents, are best.

How does the croissant craze fit in with the American passion for dieting? Probably the same way the chocolate chip cookie does . . .

In between diets.