Boston Cream Cheese Pie
["1 (9 oz.) pkg. yellow cake mix", "2 (8 oz.) pkg. Philadelphia Brand cream cheese, softened", "1/2 c. granulated sugar", "1 tsp. vanilla", "2 eggs", "1/3 c. sour cream", "2 (1 oz.) sq. unsweetened chocolate", "3 Tbsp. Parkay margarine", "1 c. powdered sugar", "2 Tbsp. hot water", "1 tsp. vanilla"]
["Grease bottom of a 9-inch spring-form pan.", "Prepare cake mix as directed on package; pour batter evenly into spring-form pan. Bake at 350\u00b0 for 20 minutes."]
["yellow cake", "cream cheese", "sugar", "vanilla", "eggs", "sour cream", "unsweetened chocolate", "Parkay margarine", "powdered sugar", "water", "vanilla"]