Step 1

, preheat the oven to 240 F/115 C.

Step 2

Using a flour sifter, sift icing (powdered) sugar and cocoa powder, and set aside. Place egg whites in a stand mixer recipient and beat until stiff. Gradually add granulated (caster) sugar and whisk until glossy. Add the dry mixture of icing sugar with cocoa powder and gently mix with a rubber spatula.

Step 3

Prepare two parchment paper sheets and draw three discs with a diameter of 6 1/2-inch/17 cm. Flip paper sheets so that the drawn circles will be facing down. Transfer the chocolate meringue in a pastry bag with Ateco plain pastry tip 809 and pipe three meringue disks in a spiral within the pencil marks.

Step 4

Also, push a few rows of long meringue sticks around disks, using the same pastry tip. Dip a knife in melted butter and cut meringue "sausages" into segments of  25/32-inch (almost 1 inch)/2 cm. Bake for 1 hour. Remove from the oven and let the meringue cool down. Break the meringue sticks.

Step 5

melt dark chocolate using a bain-marie/water bath or a microwave (mix chocolate every 30 seconds). Bring 2/3 cup + 1 tablespoons (170 g) whipping cream to a boil and pour cream in 3 times over chocolate, mixing well with the spatula. Keep the mixture at 113 F/45 C (maximum).

Step 6

In a separate bowl, whisk 1 1/2 cups (340 g) whipping cream to get a softly whipped cream. Add whipped cream to the chocolate preparation, mix and use immediately. Do not refrigerate!

Step 7

temper chocolate. Pour the tempered chocolate on a worktop surface (better marble or granite) and spread it up to 1/10-inch/2 mm thick. When the chocolate is just starting to crystallize, push it quickly with a triangle, a chocolate spatula, or a large knife. Repeat the operation several times to obtain chocolate shavings, ideally with a length of about 1 1/2-inch/4 cm. Let it completely crystallize before you use it.

Step 8

place the first meringue disk on a serving plate or a cake board, with the flat surface facing down. Cover it regularly with 6.4 oz. (180 g) chocolate mousse. Place the second meringue disc smooth side up this time. Spread 6.4 oz. (180 g) mousse again. Cover with the last disc with the flat side on the top. Cover the top and sides with the remaining chocolate mousse and smooth them with a spatula.

Step 9

Decorate the sides of the cake horizontally, placing the meringue sticks on two levels. Decorate the top of the cake with chocolate shavings. Sprinkle with the icing (powdered) sugar. Refrigerate the cake for at least 6 hours, better overnight.