The Smoothest and Best Ever Dark Chocolate Custard Ice Cream

good quality unsweetened cocoa powder, like Barry or Perugina (please do not use the standard grocery store brand as the end result will not be good)

sugar, divided in half

whole milk

( 545 ml) heavy whipping cream

large eggs, plus 4 large egg yolks

bittersweet or semisweet chocolate, coarsely chopped or chips (again, it is necessary to use good quality chocolate)

vanilla extract