Rich chocolate cake layered with chocolate frosting.
Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a large mixing bowl, combine the flour, sugar, cocoa powder, baking powder, baking soda, and salt. Whisk together until well mixed.
Add the eggs, milk, vegetable oil, and vanilla to the dry ingredients. Beat on medium speed for 2 minutes. Stir in the boiling water until well combined.
Pour the batter evenly into the prepared cake pans. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then remove from pans and cool completely on wire racks.
In a medium bowl, combine the cocoa powder and softened butter. Beat until smooth. Gradually add the powdered sugar and milk, beating until the frosting is fluffy. Stir in the vanilla extract.
Once the cakes are completely cool, place one layer on a serving plate. Spread frosting on top, then place the second layer on top of the frosting. Frost the top and sides of the cake.