- 8 oz (250 g) bittersweet chocolate, finely chopped
- ¾ cup (175 ml) hazelnuts, toasted, husked, and finely chopped
- 1 recipe Puff Pastry
- 1 egg, beaten with 2 tbsp (25 ml) water
- Turbinado or granulated sugar
- Preheated oven to 400°F (200°C)
- 2 large baking sheets, lined with parchment paper
- In a heatproof bowl set over a saucepan of hot, not boiling water, melt chocolate, stirring frequently until smooth. Remove from heat and stir in hazelnuts. Let stand over hot water while you prepare the pastry.
- On a lightly floured work surface, roll pastry out to a 25- by 10-inch (63 cm by 25 cm) rectangle. Trim edges so they are straight and cut into ten 5-inch (13 cm) squares. Divide chocolate mixture among the squares, placing the filling in the center of each square. Working with one square at a time, brush edges lightly with egg wash, then fold over the corners to form a triangle. Press down on the edges gently with the tines of a fork to seal. Make two small slits on the top of each turnover with a sharp knife. Place at least 2 inches (5 cm) apart on prepared baking sheets. Brush tops lightly with egg wash and sprinkle with sugar.
- Bake in upper and lower thirds of preheated oven for 15 to 20 minutes, rotating and switching pans halfway through, or until golden brown. Serve warm or at room temperature.