⅓ cup (3 oz./90 g) egg yolk (about 3 yolks)
¾ cup (5 oz./145 g) sugar, divided
½ cup plus 1 tbsp (4.5 oz./125 g) egg white (about 4 whites)
5 tbsp (1.25 oz./35 g) unsweetened cocoa powder, sifted
Salted butter caramel
Scant ⅔ cup (4.25 oz./120 g) sugar
½ cup (120 ml) heavy whipping cream
6 tbsp (3.25 oz./90 g) butter, diced, at room temperature
Scant ¼ tsp (1 g) fleur de sel
2¾ cups (700 ml) heavy whipping cream, divided
1 oz. (30 g) glucose syrup
0.75 oz. (20 g) invert sugar
6.75 oz. (190 g) dark chocolate, 66% cacao, chopped
10.5 oz. (300 g) cocoa butter
10.5 oz. (300 g) dark chocolate, 66% cacao
8 sheets (16 g) gelatin
2 cups (14 oz./400 g) sugar
⅔ cup (150 ml) water
1⅓ cups (5.25 oz./150 g) unsweetened cocoa powder, sifted
1 cup plus 2 tbsp (280 ml) heavy whipping cream
3½ oz. (100 g) popcorn
0.3 oz. (10 g) edible gold dust
Making the sponge layer
Preheat the oven to 410°F (210°C/Gas mark 6). Line the baking sheet with parchment paper. Whisk the egg yolks with half the sugar until pale and thick. Using the electric beater, whisk the egg whites to the firm peak stage, then incorporate the remaining sugar. Whisk until glossy. Stir the cocoa powder into the yolk and sugar mixture, then carefully fold in the whisked egg whites. Spread the batter evenly over the baking sheet and bake for 11 minutes; it should remain springy to the touch. Let cool and cut out 20 × 1½-in. (4-cm) disks.
Making the salted butter caramel
In a saucepan, make a dry caramel with the sugar: the temperature should not exceed 347°F–355°F (175°C–180°C). While the sugar is heating, scald the cream. Using a heatproof spatula, stir the cream into the caramel, taking care that it does not splutter, to prevent the caramel darkening any further. Remove from the heat and gradually stir in the butter, then the fleur du sel. Return to the heat and cook to 228°F (109°C). Let cool, then whisk lightly so it is easier to pipe out.
Making the whipped ganache
In a saucepan, heat 1 cup (250 ml) of the cream with the glucose syrup and invert sugar. Pour the liquid over the chocolate. Whisk well to form a “kernel” at the center of the ganache. Continue until thoroughly combined. Pour in the remaining cream (1¾ cups/450 ml), stir well to combine, and chill for at least 3 hours.
Making the coating and glaze, and assembling the spheres
Using a whisk, whip the ganache lightly. Transfer to a pastry bag and half-fill each mold, then pipe some salted butter caramel into the ganache. Set a disk of sponge over this layer, pressing it down slightly. Add another layer of ganache to fill the molds and top with a second sponge disk. Place in the freezer until set solid (about 2 hours). To make the coating, melt the chocolate and cocoa butter together to 95°F (35°C). Keep the temperature constant. To make the glaze, soften the gelatin in a bowl of cold water. In a saucepan, cook the sugar and water to 223°F (106°C) to make a syrup, then stir in the cocoa powder. Bring the cream to a boil and carefully stir it into the cocoa syrup. When the mixture has cooled to 140°F (60°C), squeeze the excess water from the gelatin and stir in to dissolve completely. Strain through a fine-mesh sieve so that the glaze is perfectly smooth. Remove the molds from the freezer, unmold the hemispheres, and spread a little ganache over 10 of them. Assemble the halves to make 10 complete spheres. Insert a wooden skewer carefully through each sphere and dip them into the coating. Let set for about 5 minutes, then dip into the glaze to coat. Roll the popcorn in the edible gold powder and sprinkle it over the spheres.
Extracted from Chocolate: Recipes and Techniques from the Ferrandi School of Culinary Arts (Flammarion, 2019) by FERRANDI Paris. Photography © Rina Nurra2019.