In a saucepan, add the cocoa powder and the egg yolks and whisk until there are no lumps. Add the erythritol sweetener and mix well until combined. Add the heavy cream, almond milk, and chocolate chips and stir to combine. Place the pan over medium-low heat and cook for about 7 to 8 minutes, stirring, until the chocolate melts and the mixture thickens. Add the vanilla and sea salt and stir to combine. Transfer to a bowl and refrigerate overnight.

Place in the ice cream maker and churn according to the manufacturer’s instructions. Fold in the hazelnuts quickly.

Return the ice cream to the freezer and freeze for at least 4 hours before serving.