Preheat oven to 180°C.

Mix flour, cocoa and baking powder in a bowl. In another bowl, beat softened butter and sugar until soft and light. Add one egg at a time, and stir until it is incorporated.

Stir into half of the flour and cocoa mixture and pour the milk. Fold in the rest of the dry mixture. Spoon the mixture into 16 cupcakes, filling each cup about two-thirds full.

Bake in preheated oven for about 25 minutes, then let them cool completely on a wire rack.

Whisk egg whites and sugar together in a big metal bowl over a pot of simmering water. Whisk until the albumens get white and glossy and you can’t feel the sugar granules when you rub the mixture between your fingers.

Wipe the condensation off the bottom of the bowl and transfer mixture into the mixer and whip until it turns firm, cold and about doubled in size.

Finally, add the butter a piece at a time and whip until throughly incorporated and firm. Do not panic! It will require time, but eventually it works! Fold in sieved cocoa powder.

Spoon the Swiss meringue buttercream frosting into a pastry bag and decorate cupcakes as desired. Let rest in refrigerator for at least an hour. Before serving, dust with Dutch cocoa.