Combine the heavy cream, milk, half of the sugar, cocoa powder, and chipotle powder in a medium saucepan over medium heat.
Whisk the mixture continuously until the cocoa is fully dissolved and the liquid begins to steam, but do not let it reach a full boil.
In a separate mixing bowl, whisk the egg yolks with the remaining sugar and salt until the mixture is pale and slightly thickened.
Slowly temper the eggs by pouring about half a cup of the hot cocoa mixture into the yolks while whisking vigorously to prevent curdling.
Pour the tempered egg mixture back into the saucepan with the remaining cocoa base.
Cook the custard over medium-low heat, stirring constantly with a rubber spatula, until it thickens enough to coat the back of a spoon, about 5 to 7 minutes.
Strain the custard through a fine-mesh sieve into a clean bowl to ensure a perfectly smooth consistency.
Stir in the vanilla extract, cover the bowl with plastic wrap pressed directly against the surface of the custard, and refrigerate until completely chilled, at least 4 hours.
Pour the chilled base into your ice cream maker and churn according to the manufacturer’s instructions until it reaches a soft-serve consistency.
Transfer the mixture to an airtight container and freeze for an additional 2 to 3 hours to firm up before serving.