Gianduiotti (Turin Hazelnut Chocolates)

Instructions

1. Heat the oven to 325°F (165°C). Toast the hazelnuts on a baking sheet until golden inside and fragrant, 12 to 15 minutes. Rub them in a towel while warm to remove the skins and let cool until just warm, about 30 minutes.
2. Grind the warm hazelnuts in a food processor, scraping down often, until they turn into a smooth, runny paste, 5 to 8 minutes. Add the powdered sugar and fine salt and process 2 to 3 minutes more until completely smooth.
3. Melt two-thirds (165 g) of the dark chocolate in a heatproof bowl over barely simmering water until it reaches 113 to 122°F (45 to 50°C). Take it off the heat, add the remaining chocolate and stir until melted, then stir in the hazelnut paste until glossy.
4. Temper the gianduja: stir it in the bowl, setting the bowl in a larger bowl of cool water for short spells, until it cools to 79°F (26°C). Lift it out and warm it gently over the hot water for a few seconds at a time to 84°F (29°C). A smear on parchment should set glossy and firm within 5 minutes.
5. Let the tempered gianduja stand at cool room temperature, stirring every few minutes, until it thickens to the texture of soft frosting and just holds a shape, 10 to 20 minutes.
6. Spoon it into a piping bag fitted with a 3/4-inch (2 cm) plain tip. Pipe long, thick strips onto parchment, then pinch each strip along its length with an offset spatula into a triangular ridge with a flat base, like an upturned boat.
7. Leave the strips at cool room temperature, about 60 to 65°F (16 to 18°C), until firm enough to slice cleanly, about 1 hour. Cut into 1 1/4-inch (3 cm) pieces with a knife dipped in hot water and dried, angling the ends slightly.
8. Let the gianduiotti set fully for 2 more hours before wrapping each one in foil.