SOURDOUGH TEXAS SHEET CAKE

Don’t let your sourdough discard go to waste—transform it into this indulgent and rich Sourdough Texas Sheet Cake! Bursting with chocolatey goodness and baked conveniently in a sheet pan, this recipe is the ultimate sourdough chocolate cake. It’s finished with a luscious, buttery chocolate frosting and sprinkled with crunchy pecans for the perfect decadent touch.

INGREDIENTS

Cake:

  • 1 ⅔ cups unbleached flour, spooned and leveled
  • 2 cups granulated sugar
  • ¼ teaspoon salt
  • 6 tablespoons cocoa powder, leveled
  • 1 cup salted butter
  • ¾ cup boiling water
  • ½ cup buttermilk
  • ½ cup sourdough discard
  • 2 large eggs, beaten
  • 1 teaspoon baking soda
  • 1 teaspoon vanilla extract

Frosting:

  • 1 cup chopped pecans
  • ¾ cup + 2 tablespoons butter
  • 6 tablespoons cocoa powder, leveled
  • 6 tablespoons buttermilk or whole milk
  • 1 teaspoon vanilla extract
  • 3 cups powdered sugar

INSTRUCTIONS

Prepare the Cake:

  • Preheat your oven to 350°F (175°C). Lightly grease a half-size sheet pan (about 18×13 inches) with cooking spray, butter, or oil.
  • In a medium bowl, whisk together the flour, sugar, and salt. Set aside.
  • In a medium saucepan, melt the butter over medium-low heat. Whisk in the cocoa powder until smooth.
  • Add the boiling water to the cocoa mixture and stir until fully combined.
  • Pour the chocolate mixture into the bowl with the dry ingredients. Fold together until smooth.
  • In a separate bowl or large measuring cup, combine the buttermilk and sourdough discard. Mix in the beaten eggs, baking soda, and vanilla extract.
  • Add the buttermilk mixture to the chocolate batter, stirring until well combined and lump-free.
  • Pour the batter into the prepared sheet pan, spreading it evenly with a spatula.
  • Bake for 20–22 minutes, or until a toothpick inserted in the center comes out clean.

Prepare the Frosting:

  • While the cake bakes, chop the pecans if needed.
  • Melt the butter for the frosting in a saucepan or microwave. Stir in the cocoa powder until smooth.
  • Add the buttermilk, vanilla, and powdered sugar, whisking until the frosting is silky and lump-free.
  • Stir in the chopped pecans.

Assemble:

  • Once the cake is warm but not hot, pour the frosting evenly over the top. Spread it gently to cover the entire surface.
  • Serve immediately or cover and refrigerate for a rich, fudgy texture.

NOTES

  • No Sourdough Option: To skip the sourdough discard, replace it with an additional ⅓ cup of flour and ¼ cup of boiling water.
  • Nut Substitutes: Walnuts can be used in place of pecans if preferred.