01 - In a medium saucepan, whisk together cocoa powder, sugar, and salt. Gradually add milk while whisking until smooth.
02 - Place saucepan over medium heat and bring to a gentle simmer, stirring constantly to prevent scorching.
03 - Remove from heat, add chopped dark chocolate, and whisk until fully melted and smooth.
04 - In a separate bowl, whisk egg yolks. Slowly pour about 1/2 cup of the hot chocolate mixture into yolks, whisking constantly to temper.
05 - Pour tempered egg yolk mixture back into saucepan. Return to medium-low heat and stir continuously with a wooden spoon until custard thickens and coats the back of the spoon, approximately 5 to 7 minutes. Do not allow to boil.
06 - Remove from heat and stir in heavy cream and vanilla extract until fully combined.
07 - Pour mixture through a fine mesh sieve into a clean bowl to eliminate any lumps.
08 - Cover and refrigerate for at least 4 hours, or until completely cold.
09 - Process chilled mixture in an ice cream maker following manufacturer’s instructions until the texture is creamy and firm.
10 - Transfer churned ice cream to a lidded container and freeze for a minimum of 2 hours to firm up before serving.