Chocolate, Coconut Cake
["1 pkg. white cake mix", "4 sq. unsweetened chocolate", "1 large container Cool Whip", "1 1/3 c. coconut", "2 c. (1 box) confectioners sugar", "1 egg yolk", "2 Tbsp. (large) hot water", "3 Tbsp. butter or margarine", "1 Tbsp. vanilla"]
["Prepare cake mix as directed on package.", "Chop 2 squares of the chocolate into cake mix.", "Bake cake in 4 layers."]
["white cake mix", "unsweetened chocolate", "coconut", "confectioners sugar", "egg yolk", "water", "butter", "vanilla"]