• Grease and flour two round, 9 inch cake pans and preheat oven to 350 degrees F. (Add parchment paper liners to bottom of pans for easier removal).
• In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, salt, and espresso powder.
  2 cups all purpose flour, 2 cup white sugar, 3/4 cup cocoa, 2 tsp baking powder, 1.5 tsp baking soda, 1 tsp salt, 2 tsp espresso powder
• Add the milk, eggs, melted butter, vanilla and sourdough discard and mix until just combined.
  1/2 cup milk, 1/2 cup melted butter, 2 large eggs, 2 tsp vanilla extract, 3/4 cup sourdough discard
• Slowly pour the boiling water over the ingredients and mix to incorporate. The batter will be runny.
  1 cup boiling water
• Pour the batter evenly between the two pans. Bake for 30-35 minutes or until the toothpicks come out clean. Let the cakes cool before removing from pans.

Frosting

• Sift cocoa powder into medium bowl and add room temperature butter. Cream together with a hand-held mixer.
• Sift two cups of powdered sugar into the creamed ingredients. Add two tablespoons of milk and cream together. Add additional one tablespoon of milk and one cup of powdered sugar at a time, creaming together as you go.
  1½  cups softened butter, 1 cup unsweetened cocoa powder, 1/2 cup milk, 1.5 tsp vanilla extract , 1 tsp espresso powder
• Add vanilla and espresso powder to frosting and cream together.

Assemble Cake

• Once cooled, frost bottom cake layer generously with frosting. Then add second layer and frost.