• 1 3/4 cups 1% milk
  • 1 1/2 tablespoons cornstarch
  • 1/3 cup sugar
  • 2 teaspoons Hershey's special dark cocoa powder
  • 1 teaspoon vanilla
Stir together 1/4 cup milk and cornstarch.

Whisk together sugar, cocoa, and remaining 1 1/2 cups milk in a small heavy saucepan and bring to a boil over moderate heat, stirring. Stir cornstarch mixture again and whisk into cocoa mixture. Return to a boil, whisking, then remove from heat.

Add vanilla and a pinch of salt to saucepan, stirring.

Set saucepan in a large bowl of ice water to cool, whisking frequently.

Freeze chocolate mixture in ice-cream maker. When nearly frozen, add remaining chocolate and churn until blended.