1. Preheat oven to 300°F (150°C). Spread hazelnuts on a baking sheet and roast for 10–15 minutes, until fragrant and skins blistered. Let cool, then rub in a clean towel to remove loose skins.

2. Pulse cooled hazelnuts in a food processor until finely ground but not oily. Sift in powdered sugar and salt, pulse to combine.

3. In a clean bowl, whisk egg whites until frothy. Gradually add granulated sugar, whisking to stiff, glossy peaks. Fold in hazelnut mixture in two additions until smooth and even.

4. Line a baking sheet with parchment. Spoon mixture into 16 small mounds, 1 1/2 inches apart, using two spoons for neat rounds. Smooth tops lightly.

5. Bake 18–22 minutes until firm and pale golden. Cool completely on wire rack.

6. Melt dark chocolate in a double boiler or microwave in 30-second bursts, stirring until smooth. Let cool slightly.

7. Place a small spoonful of jam on flat side of half the meringues. Top with remaining meringues to form sandwiches, pressing gently to adhere.

8. Dip the top half of each sandwich into melted chocolate to coat about 2/3 of the surface. Return to parchment.

9. Refrigerate 15 minutes until chocolate is set. Serve chilled.