Combine and smimmer milk, heavy cream, sugar, cocoa powder, and salt in a saucepan over medium heat, stirring frequently until hot but not boiling.

Whisk egg yolks and vanilla extract into a small bowl. Pour in 1/2 cup of hot milk mixture, then return to the saucepan, stirring frequently so the egg doesn't scramble (this is tempering the egg). Stir until thickened, but do not boil (low medium heat)

Remove from the heat and let cool. Once cool add the chopped chocolate. Refrigerate until cold.

Pour into an ice cream maker and freeze according to manufacturer's directions. Enjoy!