Preheat the oven to 350°F. Spray two 9" round cake pans with non-stick spray. Place a piece of parchment paper in the bottom of each pan. Spray parchment.
Whisk flour, sugar, cocoa, baking soda, baking powder, and salt in a large mixing bowl.
Add the milk, eggs, vanilla extract, and oil. Beat with a hand mixer till well combined. Slowly pour in the boiling water and beat till smooth.
Divide batter between two pans. Bake at 350°F for 35-40 minutes or until a toothpick inserted in the center comes out clean.
Cool for 8-10 minutes, then invert onto cooling racks. Cool completely.
Spread half of the frosting onto one of the cakes. Add the second layer, then spread the remaining frosting on top.