Preheat oven to 400 degrees F. Line 6 muffin cups with large paper liners
Mix flour, cocoa and sugar in a mixing bowl.
Whisk butter, egg, evaporated milk and vanilla in a separate bowl.
Add milk mixture to flour mixture and stir until just combined. Fold in chocolate chips. Spoon the mixture evenly into prepared muffin cups. Put muffins in the oven on center rack.Reduce heat to 350 F.
Bake for 17-20 minutes or until a toothpick inserted comes out with most crumbs. Cool on a wire rack
