Steps
1. Preheat the oven to 350°F (175°C).
2. Grease and flour two 9-inch round cake pans.
3. In a large bowl, mix together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
4. Add the butter, eggs, milk, and vanilla extract. Beat on medium speed for 2 minutes.
5. Stir in the boiling water until well combined; the batter will be thin.
6. Pour the batter evenly into the prepared pans.
7. Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
8. Let the cakes cool in the pans for 10 minutes, then remove to wire racks to cool completely.