Chocolate Cakes

Before starting this Gâteau Concorde by Lenôtre, organise the necessary ingredients for the chocolate meringue.
For the chocolate meringue: In a mixing bowl, sift the cocoa powder and icing sugar, using a fine sieve.
Tap the edge of the sieve with a spatula to facilitate the sifting process. Set aside.
Place the matured egg whites (ideally at room temperature) in the stand mixer recipient.
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