Preheat your oven to 350°F (175°C). This ensures that the cake bakes evenly.

Grease and flour two 9-inch round cake pans. This prevents the cake from sticking.

In a large mixing bowl, combine the sifted flour, cocoa powder, sugar, baking powder, baking soda, and salt. Whisk together to ensure even distribution of dry ingredients.

Add the eggs, milk, vegetable oil, and vanilla extract to the dry ingredients. Beat on medium speed for 2 minutes. This incorporates air into the batter, making the cake light and fluffy.

Stir in the boiling water until the batter is smooth. The boiling water helps to bloom the cocoa, enhancing the chocolate flavor.

Pour the batter evenly into the prepared pans.

Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean. This indicates that the cake is fully baked.

Remove from the oven and let the cakes cool in the pans for 10 minutes. Then, remove from pans and transfer to a cooling rack to cool completely.

In a large mixing bowl, beat the softened butter until creamy. This creates a smooth base for the frosting.

Gradually add the sifted powdered sugar and cocoa powder, mixing on low speed until combined.

Add the milk and vanilla extract. Beat on medium speed for 2-3 minutes until the frosting is light and fluffy.

Place one cake layer on a serving plate. Spread a layer of frosting on top.

Place the second cake layer on top and frost the top and sides of the cake. Use a spatula to create a smooth finish.

Optional: Decorate with chocolate shavings or sprinkles for a festive touch.