Preheat oven to 375 degrees. Mix chocolate and butter in saucepan over low heat, stirring constantly until well blended. Remove from heat. Blend in evaporated milk gradually.
In a seperate bowl, mix sugar, cornstarch and salt. Beat in eggs and vanilla. Add chocolate mixture gradually and mix thoroughly. Pour into pie shell. Combine coconut and pecans and sprinkle over filling.
Bake at 375 for 45-50 minutes or until puffed and brown. During the last 15 minutes of baking time cover loosely with foil if top browns too quickly. Cool 4 hours. Garnish with Cool Whip.