King Arthur Flour's Favorite Fudge Cake

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King Arthur Flour's Favorite Fudge Cake

star rating (37) rate this recipe »
Published prior to 2008

This old-fashioned chocolate sheet cake is incredibly moist, and can be stirred together by hand if need be. The fudge frosting is also stir-together simple, and creates a lovely thick layer on top. You can line the pan with parchment or foil before baking, grease it, and lift the cake out of the pan once it's cool before frosting. This makes cutting the cake easier to do, and individual portions nestle nicely into muffin papers. It's sure to be a hit at your next potluck. We've taken one of our commenters suggestions and doubled the cocoa in the recipe to 1/2 cup. Now it's an intensely chocolately cake.

1 cup (2 sticks, 8 ounces) butter or margarine
1/2 cup (1 1/2 ounces) unsweetened Dutch-process cocoa
1 cup (8 ounces) hot water
2 cups (8 1/2 ounces) King Arthur Unbleached All-Purpose Flour
2 cups (14 ounces) granulated sugar
1 teaspoon baking soda
1/2 teaspoon salt
1/2 cup (4 ounces) buttermilk or yogurt
2 large eggs
1 teaspoon vanilla

Quick Fudge Frosting
1/2 cup (1 stick, 4 ounces) unsalted butter
1/4 cup (3/4 ounce) unsweetened cocoa
6 tablespoons (3 ounces) buttermilk or yogurt
4 cups (1 pound) confectioners' sugar

Cake: Preheat the oven to 350°F. Grease and flour a 9" x 13" cake pan.

Melt the butter or margarine; stir in the cocoa and hot water. In a separate bowl, combine the flour, sugar, soda and salt. Pour the cocoa mixture over the dry ingredients, stirring to blend. Beat in the buttermilk or yogurt, eggs and vanilla.

Pour the batter into the prepared pan. Bake the cake for 30 minutes, or until it tests done. (You'll smell the chocolate aroma, and the cake will begin to pull away from the edge of the pan). Remove from the oven and cool on a rack.

Frosting: Melt the butter in a medium-sized saucepan. Stir in the cocoa and buttermilk or yogurt. Bring the mixture to a boil, then remove from the heat and mix in the confectioners' sugar, beating until smooth. Pour over the cake while the frosting is still warm. Serve cake right from the pan.


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  • star rating 04/10/2015
  • xochitl from KAF Community
  • This is the best chocolate cake ever!! My husband loves chocolate cake and though I make for him, it's not my fave, but this was amazing!! Can't stop at one piece! I used coffee in place of water like one reviewer suggested. Also, recipe is very easy to make. Just make sure it all gets mixed in and no clumps in cocoa.
  • star rating 03/27/2015
  • Michele from Sacramento, CA
  • This is the one! Best chocolate cake ever!! I used hot coffee instead of water and WOWZA. I've used this recipe to make cupcakes also, they turned out fantastic.
  • star rating 02/09/2015
  • Shirley from tn
  • Love double dutch cocoa from KAF!!! Can this recipe be made in loaf pans with it turning out OK? Didn't want to mess it up since it is so good.

    We haven't tried it in that pan, but you should give it a try. Bake for about 40-45 minutes. Happy baking! Laurie@KAF

  • star rating 01/21/2015
  • Mary McC from W MI
  • Easy and wonderful! I made 1/2 the recipe and baked in 4 4 1/2" mini heart springform pans - they came out perfect! So moist and delicious!
  • star rating 11/21/2014
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  • star rating 07/20/2014
  • tpel_91 from KAF Community
  • Tried this cake batter in the New England Hot Dog Bun pan per the idea in the blog post for that pan. I used a combination of natural, double-dutched and black cocoas and had closer to 2/3 of a cup total. Also substituted milk with a tsp of vinegar because I had no buttermilk on hand. I've never been one to make cake from scratch like this. But WOW, did this turn out!!! I'll be making this again.
  • star rating 06/10/2014
  • JAINIE from KAF Community
  • Excellent, a question though. Since I have gotten your pwd. buttermilk, can I sub that for the liquid buttermilk and if so, what quantity. Thanks.
    Yes, you sure may use the powder in place of fresh. Blend in 2 T. of the powder into the dry ingredients. Use 1/2 cup of water in place of the 1/2 c. of buttermilk. Enjoy! Elisabeth@KAF
  • star rating 05/12/2014
  • deadalchemist from KAF Community
  • I have made this cake twice and both times amazing! The first time I followed the recipe exactly and the second time I substituted coffee for the hot water as another reviewer suggested. I used "sea salt caramel mocha" coffee and WOW. This cake is not disappointing. I know I will return to this recipe again and again. It only lasts for a day or two because the family devours it!
  • star rating 03/13/2014
  • Grandma A from Denver, CO
  • I used half all purpose, half white whole wheat flour, and added a bit of cornstarch to the mix. Batter appeared a bit runny, so I called KAF. (Thank you, John for helping me out) It was fine, although I did go ahead an add an extra 2 TBLSP. of the all purpose flour, just to be on the safe side(I am at 5,000' altitude.) Took the cake out, and it appeared that I had over mixed a bit. I set it out to cool, and made the frosting. Was distracted by a phone call, and realized I had added too much confectioners sugar, so added about a tablespoon and a half of the Dutch cocoa to the frosting, even though I had put in regular ol'cocoa originally. Then toasted some pecans to throw in the frosting. I then went over to the almost-cooled cake and tried was just OK.... Tossed the roasted pecans in the frosting, and set it aside. Took another small piece of cake...OMG!!!! That cake had turned into cake-fudge!!! I lathered on the frosting guessed it....had another small piece. WOW!!! This is a keeper!!!
  • star rating 01/27/2014
  • lexicon159 from KAF Community
  • This is the best chocolate cake I have ever had. Moist, dense, and has such a wonderful chocolate taste. I made it exactly by the recipe but I used hot coffee instead of hot water for the liquid as per another reviews suggestion. This will be my go to cake recipe. Thanks KAF
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