Preheat the oven to 350°F (175°C) and grease two 9-inch round cake pans.
In a large bowl, combine flour, sugar, black cocoa, baking powder, baking soda, and salt.
Add eggs, milk, oil, and vanilla to the dry ingredients and mix until well combined.
Slowly stir in boiling water until the batter is smooth.
Divide the batter evenly between the prepared cake pans.
Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
Let the cakes cool in the pans for 10 minutes, then transfer to wire racks to cool completely.