Combine sugar, flour, salt and cinnamon in a 2 qt saucepan. Gradually add milk. Cook over medium heat, stirring constantly, until thickened. Cook additional 2 minutes. Remove from heat. Blend in melted chocolate. Blend a small amount of hot mixture into eggs; return all to pan, stirring constantly. Cook 1 minute (DO NOT BOIL). Remove from heat; add coconut. Cool. Blend in cream; chill. Stir in nuts. Churn-freeze.
