Instructions:

Preheat the oven to 350°F (175°C). Grease and flour two 9-inch (23 cm) round cake pans.
In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, salt, and espresso powder (if using).
In a separate bowl, whisk together the buttermilk, warm water, oil, eggs, and vanilla extract.
Pour the wet ingredients into the dry ingredients and whisk until just combined. Divide the batter evenly between the prepared pans.
Bake for 30-35 minutes, or until a toothpick inserted into the center of the cakes comes out clean.
Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.
Once the cakes are cool, you can frost and decorate them as desired.

Enjoy!