Step 1

Preheat oven to 350°F (180°C) standard or 320°F (160°C) fan/convection.

Step 2

Lightly grease 2x 9-inch (22cm) round cake pans with butter. Line base with parchment paper.

Step 3

Sift together flour, cocoa, baking powder, baking soda and salt into a large bowl. Whisk in sugar, then add eggs, milk, oil and vanilla. Whisk well to combine until lump free, about 30 seconds.

Step 4

Pour boiling water into batter, mixing well. Cake batter is thin in consistency.

Step 5

Pour batter into cake pans and bake for 30-35 minutes or until a wooden skewer inserted into the centre comes out clean.

Step 6

Let cool for 10 minutes, then turn out onto wire racks to cool completely before frosting.

Step 7

Melt butter, then whisk in cocoa powder. Alternately add powdered sugar and milk, beating to spreading consistency (add a small amount of additional milk, if needed). Stir in vanilla.