Step 1

In a medium saucepan, combine 1 cup of the cream with the cocoa powder over medium-high heat, whisking to dissolve the cocoa. Bring the mixture to a boil, then reduce heat to medium-low and simmer for about 30 seconds, whisking constantly. Remove from the heat and add the chopped chocolate, stirring until smooth, then stir in the remaining 1 cup cream. Transfer this mixture to a medium-large mixing bowl, and set a large fine mesh strainer over the top.

Step 2

In the same saucepan, combine the milk, sugar, and salt over medium-high heat. In a separate medium bowl, whisk together the egg yolks. When the milk mixture is warm, slowly pour it into the egg yolks, whisking constantly. (This is tempering the eggs.) Then, pour the egg-milk mixture back into the saucepan.

Step 3

Stir the mixture constantly over medium heat with a heatproof spatula, scraping the bottom as you go, until it thickens into a custard and coats the spatula. If you have an instant-read thermometer, it should read 170-175° F at this point.

Step 4

Pour the custard through the strainer into the chocolate-cream mixture that you previously set aside. Add vanilla extract and stir until smooth.

Step 5

Cover with plastic wrap and chill thoroughly in the refrigerator (see recipe note 1). When cold, freeze the mixture in an ice cream maker according to the manufacturer’s instructions. Store in an airtight container and freeze until ready to serve.