Dark Chocolate Buttermilk Cake

One of the absolute best chocolate cakes I’ve ever made! This cake recipe, adapted slightly from Gourmet Traveller, is super-moist, super flavorful. Not too sweet, and super-chocolatey cake is covered with a pillow of the best chocolate frosting ever – a bit of tang from the Buttermilk is positively magical!

It keeps several days, theoretically. It’d be tough to keep it that long. It’s THAT GOOD!

Equipment needed: Stand mixer or Hand mixer, and either 8×8 or 9×9 baking pan

  • Author: Laura
  • Prep Time: 25 min
  • Cook Time: 50 min
  • Total Time: 1 hour 15 minutes
  • Yield: 1 - 8x8 or 9x9 Cake 1x
  • Category: Cakes
  • Method: Baking
  • Cuisine: American



For the Cake:

  • 1 1/3 c + 1 Tbsp (280 g) Granulated or Baking Sugar
  • 4 oz. 120 g Bittersweet (70% Cocoa solids) or Semi-sweet (58-63% Cocoa Solids) Baking Chocolate
  • 6 oz. water
  • 6 T (90g) Butter, diced
  • 1 3/4 c (225g) All-purpose Flour
  • 2 T Cocoa Powder (Dutch process preferred, but not necessary)
  • 2 t Instant Espresso Powder
  • 3/4 t Baking Soda
  • 1/2 tsp Kosher Salt
  • 1/2 c (120 ml) Buttermilk
  • 1 Lg Egg
  • 1 Egg Yolk

For the Chocolate Buttermilk Frosting:

  • 5 oz (150g) Bitttersweet or Semi-Sweet Baking Chocolate
  • 7 T (100g) Softened Butter
  • 1 c (120g) Confectioners Sugar
  • 6 Tbsp (70 ml) Buttermilk
  • Pinch Kosher Salt

Optional Garnishes:

  • Flaky Sea Salt
  • Freeze Dried Strawberries or Raspberries
  • Edible Flower Petals


Make the Cake:

  1. Preheat oven to 320F (Conventional) or 300F (Convection/Fan). Butter an 8×8 pan (9×9 is ok, too!). Line with parchment if you want to remove it from the pan to serve. Chop the chocolate.
  2. Combine the sugar, chopped chocolate, butter and water in a large saucepan. Stir occasionally over low heat until just melted and smooth. It should not be hot to the touch, rather just warm. Remove from heat, cool slightly. 
  3. Sift the flour, cocoa, espresso powder, baking powder and salt into the saucepan with the butter and chocolate mixture.
  4. Whisk in buttermilk, egg and yolk until smooth. Pour into baking pan and bake until you can touch the center and it springs back, and it has just begun to pull away from the sides of the pan. This will take 45-50 minutes in an 8×8 pan, or 42-48 mins in a 9×9 pan. Cool the cake in the pan. 

Make the Frosting

  1. Chop the chocolate. In a heatproof bowl over a saucepan of simmering water, melt the chocolate. Stir occasionally until just melted and smooth. It should not be hot to the touch. Remove from the heat and set aside for 5 minutes or so until it has cooled slightly.
  2. Scrape into the bowl of a stand mixer, or a bowl you can use with a hand-mixer. Add the butter and beat until fluffy. This may take awhile, but after 6-10 minutes at high speed, it should become fluffy. See my photo.
  3. Beat in the confectioners sugar and buttermilk until smooth and spread across the cooled cake. Top with flaky sea salt, rose petals or dried strawberries or raspberries if desired.


  1. Cake will be fresh at room temperature when covered loosely for at least 2 days. If you want to keep it longer than 2 days, I recommend covering with plastic or in a dish with a plastic top, and refrigerating. Bring to room temperature, if desired, prior to serving.


Keywords: Chocolate Buttermilk Cake, Dark chocolate Cake, chocolate buttermilk frosting, recipe, Snack cake, dark chocolate

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