Tear up angel food cake into pieces and place in a 9 x 9 inch cake pan. Prepare a 5 ounce package of instant vanilla pudding according to package directions except to add an extra 1 teaspoon vanilla extract. Spoon over angel food cake in pan. Spoon a small carton of Cool Whip over the vanilla pudding. Sprinkle crushed Heath candy bars over the top. Chill.