• Preheat oven to 350°F. Butter and line three 9" round cake pans.
• Sift cocoa into a medium bowl. Stir in the boiling water and half of the milk, gently whisk until smooth and add remaining milk. Set aside to cool.
  1/2 cup plus 1 Tbsp unsweetened cocoa, 1/4 cup plus 2 Tbsp boiling water, 3/4 cup warm milk
• In another bowl, whisk together cake flour, baking soda and salt, set aside.
  2 & 1/4 cups sifted cake flour, 3/4 tsp baking soda, 1/2 tsp salt
• Using an electric mixer, beat butter for 3-5 minutes until light and fluffy, gradually beat in sugar and vanilla.
  1 cup unsalted butter, 1 & 3/4 cups granulated sugar, 2 tsp vanilla
• Then mix in eggs, one third at a time.
  3 large eggs
• With the mixer on low, add the flour and cocoa mixture a little at a time in alternating batches, starting and ending with the flour. Beat until just combined.
• Divide batter among the 3 prepared pans, smooth tops with an offset spatula and bake for about 20 minutes or until a toothpick inserted into the centre comes out clean. Be careful not to over bake. Sit pans on wire racks to cool for 15 minutes, then turn out cakes onto the wire racks to cool completely. Trim tops of cake layers to level before frosting.

For the frosting:

• In a small bowl, whisk together the cocoa powder and warm water until all of the cocoa is dissolved.
  1/2 cup plus 1 Tbsp unsweetened cocoa, 1/2 cup plus 1 Tbsp warm water
• Using an electric mixer, beat butter, sugar and salt until pale and fluffy.
  1 & 1/2 cups unsalted butter, 3/4 cup powdered sugar, 1 tsp salt
• Slowly beat in melted chocolate and then cocoa solution until smooth and what you'll get is a lovely dark, glossy and rich chocolate frosting. It will be hard not to put your face in the bowl.
  4 & 1/2 cups (1 & 1/2 pounds) semi-sweet chocolate chips
• Spread about 1/3 of frosting between each layer and spread the remainder of the frosting on top and sides of cake.