Sift the icing sugar, ground almonds, flour and cocoa powder together into the bowl of a mixer and add the eggs, a little at a time, and mix until combined. Whisk the egg whites to stiff peaks and slowly add the sugar. Carefully fold in the almond/icing sugar mixture then the butter and the melted cocoa paste. Spread onto a silicon mat to a thickness of 2.5 cm. Bake in the oven at 220°C for 6 min. Cut out 3 cm diameter discs of Joconde biscuit sponge.
Bring the milk and 1/3 of the sugar to the boil. Blanch the egg yolks with the remaining sugar. Pour a small amount of boiling milk onto the blanched egg yolks and combine. Heat the mixture with the rest of the milk to 85°C. Pour onto the chopped chocolate. When the mixture cools to 40°C, fold in the whipped cream.
Make a crème anglaise using the same method as for the dark chocolate mousse. Pour onto the chopped white chocolate. Fold in the whipped cream and the candied orange brunoise.
Pour the hot cream, to which instant coffee has been added, onto the chopped chocolate. Refrigerate overnight then whip like a Chantilly cream.
Melt the chocolate to 31°C. Pour a very thin layer onto an acetate guitar sheet. Leave to set then cut out 3 cm diameter rounds.
Bring the water and sugar to the boil. Cool then add the coffee extract. Use a pastry brush to imbibe the Joconde biscuit sponge with syrup.
Pipe a layer of dark chocolate mousse (20 g) into the glass. Add a disc of Joconde biscuit sponge. Pipe a layer of creamy white chocolate (10 g) on top. Add a chocolate drop. Using a star shaped nozzle, pipe a layer of milk chocolate Chantilly (15 g) on top. Decorate with candied orange peel and chocolate balls.