My friend Susan’s mother passed away recently, just two weeks shy of her 99th birthday.  With her went the secret to some of the best brownies I’ve ever eaten.

Sylvia Cohen was a charming, gracious and accomplished woman who graduated from Radcliffe in an era when few females went to college. As was expected at the time, she gave up her personal ambitions to raise three children and support the academic career of her husband, Nathan Cohen, who went on to become dean of the School of Social Welfare at UCLA.  She was a lifelong defender of social justice and surely wouldn’t have considered her brownies a significant contribution to the world.

Yet her incomparable brownies came up time and again as her family remembered this remarkable woman last month.  Although Sylvia had shared her recipe freely, no one else had ever achieved the voluptuous texture that she did using the most common ingredients: Baker’s unsweetened chocolate, margarine, sugar and flour.  Her brownies were dense, moist and incredibly silky with a generous portion of walnuts for a crunchy counterpoint.

“It was the consistency that was so amazing,” Susan recalls.

Some things are clear.  Everyone knew that Sylvia undercooked her brownies.  As soon as they came out of the oven, she topped them with waxed paper, bundled them in a towel and whisked them into the freezer.  When they were cooled, she trimmed off the edges, keeping only the fudgy center, before returning them to the freezer.  In later years, she served them straight out of the freezer, which only seemed to improve their already irresistible texture.

But why couldn’t anyone else get the same results?  I’ve made variations on the recipe several times in the last couple of week and I suspect, in part, it may be an issue of ingredients. No one I know still cooks with margarine, much less the same brand Sylvia preferred.  Some family members think she might have used Imperial, the brand with a crown on the box.

Flour, too, can make a great difference.  A moderate protein flour, such as bleached all-purpose Gold Medal, delivers a more tender crumb than the higher protein unbleached flour that many cooks use today.

Technique and experience also are critical.  Chocolate is a delicate ingredient and needs to be treated gently, warmed just enough to melt.  Alice Medrich, who knows chocolate better than anyone, calls for melting chocolate and butter in a heatproof bowl set in a wide skillet of barely simmering water so you can monitor the temperature of the water easily.

Perhaps just as important, only Sylvia knew what her brownies should look like when they were done.   By trial and error, I finally decided the edges should be set and look a little dry while the center should have lost most of its gloss and be just firm enough to touch lightly.  A toothpick stuck in the center should come out very moist.

Baking at the right temperature is essential, too.  Since ovens vary widely–mine runs almost 50 degrees colder than what it says on the dial– it’s a good idea to use a thermometer to ensure the correct setting.

In the end, it seemed foolish to try to replicate Sylvia’s brownies.  I’m not going to cook with margarine, nor do I want to use ordinary baking chocolate when there’s so much better quality available now.  Instead, I took her brownies as inspiration for a new recipe made with the best ingredients I could find.  I also opted to wrap the baked brownies tightly in heavy duty foil rather than a towel before stashing them in the freezer.  They fit better that way.

If the texture isn’t quite the same, the flavor is remarkable.  Good chocolate–I like Scharffen Berger unsweetened–contributes a fruity note and faint undertones of cinnamon while brown sugar brings a new layer of complexity.

These brownies are my tribute to Sylvia, who proved once again that good food makes great memories.