Start by heating your oven to 350°F (175°C). Grease two 9-inches round cake pans and line the bottoms with parchment paper so nothing sticks.

Grab a big bowl and mix together the flour, cocoa powder, baking powder, baking soda, salt, and sugar. Stir it well so it’s all even.

In another bowl, whisk the eggs with the milk, vegetable oil, and vanilla until smooth. Pour the wet stuff slowly into the dry stuff and mix gently until the batter is smooth, no lumps. Carefully add the boiling water and stir it in. Don’t worry if it’s thin, that’s how it should be.

Split the batter evenly into the two pans and put them in the oven. Bake 35–40 minutes, or until a toothpick comes out clean. Let the cakes cool in the pans for 10 minutes, and then move them to a wire rack to cool completely.

While that’s cooling, make the coconut buttercream. Beat the butter until creamy. Add powdered sugar, vanilla, coconut extract, and a pinch of salt gradually. Add milk a little at a time until smooth, then fold in shredded coconut gently.

Once the cakes are cool, place one on a plate and spread a layer of buttercream over it. Put the second cake on top and cover the whole thing with the rest of the frosting. Sprinkle some extra shredded coconut on top if you want it to look nice.