How to Make It
Combine sugar and cocoa in a medium, heavy saucepan over medium-low heat. Add 1/2 cup milk and egg yolks, stirring well. Stir in remaining 2 cups milk. Cook 12 minutes or until a thermometer registers 160°, stirring constantly. Remove from heat.
Place cream in a medium microwave-safe bowl; microwave at HIGH 1 1/2 minutes or until cream boils. Add chocolate to cream; stir until smooth. Add cream mixture to pan; stir until smooth. Place pan in a large ice-filled bowl. Cool completely, stirring occasionally.
Pour mixture into the freezer can of an ice-cream freezer; freeze according to manufacturer's instructions. Spoon ice cream into a freezer-safe container; cover and freeze 1 hour or until firm.