Frosted Chocolate Buttermilk Sheet Cake
Cook time
Total time
Serves: 24 squares
  • 2 cups all-purpose flour
  • 2 cups granulated sugar
  • 1 teaspoon baking sda
  • ¼ teaspoon salt
  • 1 cup water
  • 1 cup unsalted butter, room temperature
  • ⅓ cup unsweetened cocoa powder
  • 2 eggs
  • ½ cup buttermilk
  • 1 teaspoon vanilla extract
  • ¼ cup unsalted butter, room temperature
  • 3 tablespoons unsweetened cocoa powder
  • 3 tablespoons buttermilk
  • 2¼ cup powdered sugar
  1. Preheat the oven to 350 degrees F and line and/or grease a 9x13 pan. I always line my pans with foil or parchment paper because this allows me to easily lift the cake out of the pan without having to cut the cake from an awkward angle.
  2. combine the flour, sugar, baking soda, and salt in a medium bowl and set aside. In a medium sauce pan, combine the water, 1 cup unsalted butter, and ⅓ cup cocoa powder. Melt together and bring to a boil for just a moment, then add to the flour mixture and beat together until just combined. Beat in the eggs one at a time, then add the buttermilk and vanilla.
  3. Pour the cake into your prepared pan and bake for 35-40 minutes, until set. Allow to cool completely before frosting and slicing.
  4. While the cake cools, make the frosting by melted together ¼ cup unsalted butter, 2 tablespoons of unsweetened cocoa powder, and 3 tablespoons of buttermilk. When smooth, place in a large bowl and beat together with 2¼ cup powdered sugar and 1 teaspoon of vanilla. Add a bit more buttermilk or water if the consistency seems to thick, or add a bit more powdered sugar if it seems to thin.
  5. When the cake is cooled, frost and slice into 24 squares. Enjoy!
Adapted From
Recipe by The Crepes of Wrath at