Instructions: For years it was considered the poor substitute for chocolate, a pallid powder that needed major help from margarine and still could not produce a decent brownie.

But lately cocoa has been turning up on all the best shelves. High-end chocolate producers such as Valrhona, Scharffen Berger and Fauchon now make cocoa powders that leave Hersheys in the dust. I first noticed the phenomenon a couple of years ago in France, where every good chocolatier sells bags of cocoa, but lately even U.S. supermarkets carry Ghirardelli alongside the Nestles and house brands, and some natural food stores offer a choice in organic cocoa.

This month, in a whirlwind of shopping and baking, I was able to buy and try no fewer than 15 varieties. I made shortbread, muffins, two kinds of cookies and many cakes, using powders that cost as little as $2.50 and as much as $16 for about half a pound.

What I found would surprise any baker accustomed to starting a dessert recipe by melting a pound of pricey chocolate with a stick or two of equally extravagant butter. Cocoa, even inexpensive cocoa, has a deep, dark intensity of flavor and a versatility that even the best brands of 77 percent cacao chocolate lack. It cannot replace chocolate. But in recipes designed to make the most of its sharp taste and chemical capabilities, nothing works better than pure cocoa.

The explosion in the cocoa category is all the more surprising, considering how completely the powder fell out of favor in the age of excess that followed the era of fat fears, as Americans traded Snackwells for molten chocolate cakes.

If a pastry chef picked up a container of cocoa, it was only to dredge chocolate truffles or sift over tiramisu. Today, cookbooks by pastry wizards such as Claudia Fleming do not even mention cocoa in the index.

But in their rush to melt high-quality chocolate in increasingly extravagant quantities, chefs and recipe writers lost touch with a remarkable ingredient. It was as if they had abandoned mushrooms after discovering black truffles. One is not better than the other. They just have to be treated differently.

In my experience, cocoa does more than intensify flavor and sharpen edges. It also creates a moist, perfect crumb in a cake, a crisp bite in a cookie. As it blends into dry ingredients, it transforms the results no less than baking powder does.

The big lie of baking is that three tablespoons of cocoa powder combined with one tablespoon of fat can replace an ounce of chocolate. Every basic cookbook repeats it, but I learned at any early age that Betty Crocker was fooling.

Nothing replicates the richness of chocolate.

Instead, cocoa works best in recipes designed for it. Buttermilk brings out its tanginess, and the two combine to produce a springy texture in a cake. Even something as simple as the classic Amazon, or black-bottom, cake found in so many cookbooks uses no dairy products or eggs, only vegetable oil and vinegar with cold water. The cocoa reacts to the combination to produce the darkest, most moist cake seen outside the photo on a box of mix.

Until recently, I always thought the type of cocoa made a difference. I had switched to Droste, a Dutch brand, about 18 years ago after discovering how much better it worked in baking than Hersheys. But todays cocoas are almost evenly divided between Dutch style, like Droste, and natural style, like Hersheys. And all have their advantages.

The first step in producing any cocoa powder is always the same: After cocoa butter is extracted from cacao, the pods are pressed again to make a cake with no fat, just flavor.

What happens next separates the sharp from the mellow. If the cake is merely converted into a powder, it is considered natural and has a more aggressive, unadulterated chocolate taste. But if it is first Dutched, or treated with an alkali like potassium carbonate (similar to sodium bicarbonate), the color and flavor are enhanced. Alkalization makes a mellow cocoa, but it can also be a way of camouflaging inferior cocoa beans.

Not all labels disclose the type of processing, but you can guess a brand is natural if the box says 100 percent cocoa. Many either say Dutch process or list alkali as an ingredient.

Some of the newly available cocoas have a powerful chocolate taste even though no alkali is involved. Still, the Dutched varieties are almost uniformly excellent.

Cocoa has a huge advantage over chocolate for a home cook because it is so easy to work with. No melting is required, only a little sifting at most. It will never seize up or turn bitter as chocolate can.

To me theres one more advantage: Cocoa is tidier than chocolate. Chocolate leaves a kitchen looking like a crime scene. After working with cocoa, you need only dust.

If you would like to email yourself the recipe for later use, or share the recipe with your friends or family, enter the email addresses below and this recipe will be emailed to you and others as well.