Preheat your oven to 180ºC (350°F) and grease two round baking pans (8 inch).
Sift sugar, flour, cocoa, baking powder, baking soda, and salt in a big bowl.
2 cups sugar, 1 ¾ cups all-purpose flour, ¾ cup unsweetened cocoa powder, 1 ½ teaspoons baking powder, 1 ½ teaspoons baking soda, 1 teaspoon salt
In another bowl, mix eggs, buttermilk, oil, and vanilla with an electric mixer until creamy.
2 large eggs, 1 cup buttermilk, ½ cup vegetable oil, 2 teaspoons vanilla extract
Combine the wet and dry ingredients, then stir in boiling water. The batter will be thin.
1 cup boiling water
Pour the batter into the prepared pans and bake for 25-35 minutes until a toothpick comes out clean.
Let the cakes cool for 5 minutes, then remove them from the pans and let them cool completely on wire racks.