Preheat & Prep: Heat oven to 350°F (175°C). Grease and flour two 9-inch cake pans.
Mix Dry Ingredients: Whisk flour, sugar, cocoa powder, baking powder, baking soda, and salt in a large bowl.
Combine Wet Ingredients: Add eggs, milk, oil, and vanilla. Beat until smooth, then stir in boiling water (batter will be thin).
Bake: Divide batter into pans. Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
Cool Cakes: Let cool in pans for 10 minutes, then transfer to wire racks.
Make Frosting: Beat butter until creamy. Gradually mix in powdered sugar and cocoa, then add milk and vanilla. Beat until fluffy.
Assemble & Frost: Spread frosting over the first layer, add the second, and coat the entire cake in rich chocolate frosting.

Flavor-packed moments!