Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, or line them with parchment paper.

In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined.

Add the milk, vegetable oil, eggs, and vanilla extract to the dry ingredients. Mix on low speed with an electric mixer until everything is well combined.

Increase the mixer speed to medium and beat for 2 minutes. The batter will become smooth and creamy.

Stir in the boiling water until the batter is smooth. The batter will be thin, but that's okay.

Pour the batter evenly into the prepared cake pans.

Bake for 30-35 minutes, or until a toothpick inserted into the center of the cake comes out clean.

Remove the cakes from the oven and let them cool in the pans for 10 minutes.

Remove the cakes from the pans and transfer them to a wire rack to cool completely.

Once the cakes have cooled, you can frost them with your favorite frosting, or serve them as is.