Heat oven to 180°C (170°C for dark or nonstick pan). Spray bottom only of 13x23cm pan.
In large bowl, beat cake mix, water, oil, egg whites and coconut essence with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Pour into pan. Bake as directed on box for 13x23cm pan.
Cool 5 minutes. With long-tined fork, poke top of hot cake every 1cm, wiping fork occasionally to reduce sticking. In medium bowl, mix milk, 180ml of the whipping cream and the shredded coconut with whisk until blended. Microwave on High about 1 minute 30 seconds or until heated. Carefully pour mixture over top of warm cake. Cover; refrigerate 3 hours or until chilled.
In small bowl, beat remaining whipping cream with electric mixer on high speed until stiff (do not overbeat). Spread over cake; sprinkle with coconut.
Cut cake into squares; serve with any remaining cream mixture from pan. Garnish with kiwifruit. Store covered in refrigerator.