In a large saucepan, whisk together whole milk, heavy cream, cocoa powder, cinnamon, chili powder, and chipotle pepper. Heat over medium heat until mixture comes to a simmer. Take off the heat.

Stir in semi-sweet chocolate and vanilla and stir until chocolate has melted.

Put back on the heat and add 3/4 cup sugar, whisking occasionally.

In another large bowl, whisk together the rest of the sugar and egg yolks until they are thick. Slowly add the milk mixture to the eggs, whisking constantly until both mixtures are combined.

Pour the cream back into the saucepan and cook over medium heat until custard coats the back of a spoon.

Pour the custard through a fine mesh sieve into a large bowl. Place that bowl into an ice bath and allow to cool.

Chill custard in the fridge until really cold or overnight.

Churn custard in your ice cream maker according to manufacturers instructions.

Pour into a container and store in freezer.