Prepare a saucepan with simmering water covered with a heatproof bowl, ensuring the bottom of the bowl does not touch the water. Heat the chocolate. Stir until smooth, keeping in mind that Oaxacan chocolate is more coarsely ground and will have a thicker consistency than most European chocolates.

In a blender, mix chocolate, cream, and evaporated milk. Blend until you get a very smooth mixture. Refrigerate for 2 hours to overnight.

Pour into an ice-cream machine and follow manufacturer’s instructions. If you don't have an ice-cream machine, empty the mixture into a plastic container, put it in the freezer, and leave it for about an hour. When the ice cream is half frozen, transfer to a bowl and beat with an electric mixer or a balloon whisk until fluffy. Return the ice cream to the plastic container and place in the freezer for several hours to harden. Sprinkle the ice cream with red chile powder and serve.