Preparation -
In large bowl, beat the cream cheese until light and fluffy. Add the cocoa and flour and beat again. Add the sweetened condensed milk, egg whites, egg, and vanilla. Beat until all the ingredients are well blended. Stir in the chocolate chips. Pour the mixture into the pan, over the graham cracker crust. Bake in a preheated oven at 300º for 45 to 50 minutes or until the center is set. Place on wire rack. Loosen the cheesecake from the rim of pan. Cool completely before removing the sides of the pan, then refrigerate the cheesecake for several hours before serving.