Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a large mixing bowl, sift together the flour, cocoa powder, baking powder, baking soda, and salt.
In another bowl, whisk together the sugar, eggs, milk, oil, and vanilla extract until well combined.
Gradually add the dry ingredients to the wet ingredients, mixing gently until just incorporated.
Carefully add the boiling water to the batter, mixing until smooth. The batter will be thin, which is normal.
Pour the batter evenly into the prepared cake pans and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes before transferring them to a cooling rack to cool completely.
Once the cakes have cooled, frost with your favorite chocolate frosting.
