Count me among the admirers of Laurie Colwin! She was also a great fiction writer. One of my favorites of hers was "Goodbye Without Leaving." I miss her!

Good luck on your cake search, amysarah. Glad someone else out there loves Colwin, whose death was so untimely. I've read her two 'Home Cooking" books any number of times now, and I've never grown tired of them, even though her little daughter Rosa, who figures throughout, must be entirely grown up. To my ear, the blogger Molly Wizenberg sometimes has a voice that resembles Colwin's.

mainecook61, absolutely I know Laurie Colwin! Going to date myself, but besides her food writing (Gourmet columns, as well as Home Cooking) I fondly remember her short stories in the New Yorker. Good stuff. (In fact, I still do a variation of her famous baked chicken thighs all the time - the ones that bake for a crazy 2-2.5 hrs, coated in garlic, Dijon, etc. and rolled in bread crumbs.) But, I don't think this cake was hers, because it definitely had eggs in it.

Anyway, there are so many great possibilities posted here that I have a feeling there will be many chocolate cakes in my family's near future. Thx again!

The 1965 Fannie Farmer Cookbook has something very similar to @mainecook61. Higher heat different flour, cocoa powder, salt and vanilla amounts. Still without eggs.

I wonder if you're thinking of the one that Laurie Colwin writes about in "More Home Cooking." It's a simple one-bowl cake that came to Colwin from her friend Karen Edwards, who got it from Marion Cunningham's revision of the Fanny Farmer Cookbook. Colwin, in her little essay on chocolate cakes, calls it "Karen Edwards's Version of Buttermilk Cocoa Cake."
1. Preheat the oven to 350 and butter and flour a 9" round cake pan.
2. Combine 1 3/4 cups flour, 3/4 cup cocoa powder, 1 cup sugar, 1 tsp. baking soda, 1/4 tsp. salt.
3. To these ingredients add 1 cup buttermilk, 1/2 cup vegetable oil or melted butter, 2 tsp. vanilla. Mix.
4. Bake cake 30 minutes or until it tests done; cool in pan for five minutes before turning it out.

And if you haven't read Colwin ("Home Cooking" and "More Home Cooking"), you've got a treat coming that's better than cake.

The February 2011 Bon Appetit on page 91 has a really good looking chocolate cake w/ buttermilk, also has brown sugar in the ingredients.

Sounds like a time to look at the old-fashioned recipes in my Mennonite Community Cookbook (they are experts in pastry!). Mahogany Cake calls for thick sour milk, I bet buttermilk would be apt. I have used a buttermilk cake recipe from here with great success, but it's not chocolate so I'll just give you Mahogany cake.

Mahogany Cake from Mennonite Community Cookbook (ed. Mary Emma Showalter, copyright 1950!)
3/4 cup shortening
2 cups brown sugar
3 eggs
3 cups cake flour
1/2 teaspoon salt
1/2 teaspoon baking soda
1 teaspoon baking powder
4 tablespoons cocoa
1 1/2 cups "thick sour milk"
1 teaspoon vanilla

[use the regular creamed shortening-sugar method, adding sifted dry ingredients alternately with sour milk and vanilla. Bake in 2 greased 8-inch pans at 350 for 25 to 30 minutes. According to the recipe "This cake is milder in flavor and lighter in color than the usual chocolate cake" so it may not be the rich cake you are craving, but I find these recipes, which do not shy away from something like "2 cups brown sugar" tend to be rich in their own right.

The Hershey's cocoa box recipe is a longtime 'go to' cake for me as well...made on more kids' birthdays than I can count.

But, the one I'm craving now uses buttermilk and is really moist and rich. Can't believe I didn't notice the bundt cake recipe right on top of this page until drbabs pointed it out - but it sounds like it fits the bill. Thanks for the recipes, all. May have to try them all, one by one...

Ina Garten's Beatty's Chocolate Cake on the food network site is an easy and delicious buttermilk chocolate cake. . I've tried a many, many chocolate cakes, and like the first commenter, bexcahlik, that Hershey recipe is my favorite too. I just keep going back to it. ( I do make some modifications). .It's not a buttermilk cake, though..

I've made the chocolate bundt cake on this page with buttermilk in place of the soured milk and it was delicious.

Here's one on food52 that Amanda and Merrill like a lot:
http://www.food52.com/recipes/133_not_red_velvet_cake_with_fudge_glaze

;o)

I wouldn't substitute buttermilk in a cake recipe unless I also knew how to adjust the chemical leavening agents (the baking soda, if called for, or the baking powder, which includes soda). The two react, and when not in balance, you can get a bitter aftertaste or other undesirable chemical flavor. (There is a thread about this on foodpickle, which I started about a month ago, and which led to some very interesting research and discoveries on my part.) That said, I remember a recipe with clabbered milk and cocoa that my mother made when I was growing up. I'll see if I can track it down. (It's not in my digital recipe file, but I may be able to get my hands on it in hard copy.) Stay tuned . . . . ;o)

I would recommend Hershey's Perfectly Chocolate Chocolate Cake. The recipe doesn't call for buttermilk, but I'm sure buttermilk would only improve it. This is my family's go-to birthday cake (or any time we want chocolate cake). Also comes with a good icing recipe.

http://www.hersheys.com/pure-recipes/184/HERSHEY'S