To Prepare the Toasted Hazelnuts
Combine the hazelnuts with the sugar and brandy. Toast in a 175°C/350°F oven until golden brown. Allow to cool completely.
To Make the Gianduja
- Combine the praline paste and the melted dark chocolate.
- Add the toasted hazelnut mixture. Table to temper.
- Spread the gianduja into a frame 12 × 24 × ¼ in. Allow to crystallize until set.
- Place another frame 12 × 24 × ¼ in on top of the one containing the gianduja.
To Make the Passion Fruit Ganache
- Combine the cream and glucose syrup in a saucepan. Bring to a boil. Remove from the heat and add the reduced passion fruit purée.
- Allow the mixture to cool to 40°C/105°F.
- Stir the butter into the tempered white chocolate, taking care that no lumps of butter remain.
- Pour the cooled cream mixture over the white chocolate mixture.
- Using a spoon or spatula, stir in vigorous small circles outward to emulsify.
- Stir outward in larger circles to spread the emulsion throughout the bowl, checking to see that all of the chocolate has melted. If necessary, heat the ganache over a hot water bath to melt the chocolate. The temperature of the ganache should not exceed 34°C/94°F.
- Pour the ganache immediately into the frame on top of the gianduja. Cover with plastic wrap and allow to crystallize overnight.
To Complete the Passion Hazelnut Bars
- Remove the frames from the slab.
- Precoat the gianduja side of the slab with the tempered dark chocolate.
- Cut into bars 19 mm × 8 cm/¾ × 3 in. Enrobe in the tempered dark chocolate. When the chocolate begins to set, garnish each bar with a diagonal line of toasted granulated hazelnuts. Pipe a line of the tempered dark chocolate on either side of the hazelnuts.