Preheat your oven to 350°F (175°C).
Grease and flour two 9-inch round cake pans.
In a large bowl, combine flour, sugar, cocoa powder, baking powder, baking soda, and salt.
Add eggs, milk, oil, and vanilla to the dry ingredients and beat on medium speed for 2 minutes.
Stir in boiling water (the batter will be thin).
Pour the batter evenly into the prepared pans.
Bake for 30-35 minutes, or until a toothpick comes out clean.
Let cakes cool in pans for 10 minutes, then remove and cool completely on wire racks.
Once cooled, frost with chocolate frosting as desired.