Bitter chocolate ice cream with hazelnuts

Very intense and creamy, though, not too heavy.
Here app. 6 scoops.

100g bitter chocolate
100g dutch cocoa powder
4 egg yolks
500ml milk
10g vanilla powder sugar
handful crashed hazelnuts (walnuts will be great)

Melt chocolate in milk with cocoa powder, do not boil.
Whisk yolks with sugar and vanilla until very thick.
Pour hot chocolate mixture over yolks, stirring all the time.
Stir in nuts.
Pour into air tight container, freeze for several hours, better overnight. There is no need to stir it anymore, the texture will remain soft and creamy.
Before serving place container in the fridge for 15 minutes.