Positively chocolate

Butter and flour a tin or an 7-inch (18-cm) square dish, 2 inches (4 to 5 cm) deep. Chop then melt the chocolate in a bain-marie. Mix the ingredients in the order given, then add the melted chocolate. Pour into the tin. Cook at 350°F (180°C) for 25 minutes—it should look undercooked. Turn it out onto a cooling rack and remove the tin; leave to cool.

Sifting flour eliminates lumps and gives a fine, regular powder.

Whip the yolks and sugar in bowl; boil the milk and cream; pour the liquid little by little on to the egg mixture while continuing to whip. Pour into a saucepan and cook as a custard to 183/185°F (84/85°C). Put the chopped chocolate into a second bowl. Pour on half of the custard, then mix. Pour on the remaining custard and mix.

Wash out the tin, butter it, and sprinkle it with sugar. Put the cooled melted chocolate biscuit in the bottom.

Pour the cream over the biscuit and leave in the refrigerator for 3 hours.

Melt the butter and cocoa paste at 110°F (45°C) in the bain-marie. Mix the almond praline and the hazelnut paste, cocoa paste, and butter, then add the crumbled Gavottes and the cocoa nibs. Lay 5 oz (140 g) of dark chocolate praline on the cold cream. Spread, using an offset spatula, and place in the freezer.

Break up the chocolate and melt it in a bain-marie. In a second saucepan, boil the milk, then pour it on the chocolate. Mix, then add the egg yolk. Place the egg whites in a bowl and whip them energetically, while incorporating the sugar, pinch by pinch. Work the egg white, beaten to soft peaks, into the chocolate mixture. Mix gently by lifting spoonfuls from the center to the edges, while turning the bowl. Pour the mousse into the mold over the dark chocolate praline; smooth to flatten. Place in the freezer for at least 2 hours.

Break the chocolate into pieces; put it in a large saucepan with the water, sugar, and cream. Bring to a boil over low heat; leave to boil over low heat, while turning with a spatula until the sauce coats the spatula and is perfectly smooth. Set aside 3 1/2 oz (100 g) for the icing; keep the remainder to accompany the cake.

To be glossy and crunchy, the chocolate must undergo a special treatment, due to the physical properties of the cocoa butter it contains. Its greatest enemy is water, which thickens it and causes irreparable damage.

Grate the chocolate. Boil the cream in a saucepan, take it off the heat, and add the chocolate while stirring slowly with a spatula. Leave the mixture to cool to under 140°F (60°C) before mixing in first the butter then the chocolate sauce, stirring as little as possible. The icing must be used warm, at 95/100°F (35/40°C). Using a ladle, pour it on to the cake and spread it with a long, supple spatula. If it cools too quickly, reheat it slightly, without working it, in a warm bain-marie.

Chop the chocolate and melt it in the bain-marie, over a low heat. Take it off the heat and leave to cool. In the bain-marie reheat it very lightly while mixing (at about 87°F/31°C). On a sheet of plastic, spread a thin layer of chocolate. Just before the chocolate sets, cut a thin layer of chocolate 7 by 7 inches (18 by 18 cm). Place another sheet of plastic and a book on top to keep the chocolate from distorting. Place in the refrigerator for 45 minutes. Peel off the plastic and lay the chocolate on the cake.

Keep refrigerated until ready to serve.

Decorate the cake with some edible gold leaves.