Heat the oven to 180C and spread out the nuts in a single layer on a baking sheet. Bake for about 12-15 minutes until golden, then allow to cool.
Grind hazelnuts into a smooth paste in a food processor, scraping down the sides as needed.
Melt the chocolate, then combine with the hazelnut paste.
Heat milk, milk powder, and sugar in a pan, then pour into the hazelnut-chocolate mixture.
Add vanilla and salt, adjust sweetness to taste, stir in any reserved nuts, then pour into a container and chill until set.
