Before glazing the cake pieces, place a large sheet of wax paper or plastic wrap underneath the wire rack to catch the excess chocolate glaze drippings.
Use a moistened serrated knife to cut the cake as directed, cleaning the knife blade between each cut.
Chocolate frosting and glaze can be made the day before. Store in covered container in refrigerator until ready to use. Remove from refrigerator and let stand at room temperature to soften before using. If desired, place glaze in microwavable bowl and microwave on HIGH 1 to 2 min. or until desired consistency, stirring after each min.