Preheat oven to 170°C (150°C fan-forced) and line an oven tray with baking paper.
To make the pavlova: Place 140ml lukewarm water into a large mixing bowl. Carefully add pavlova mix. Beat with an electric mixer on a low speed for 15 seconds. Increase the speed to high and beat for 4-7 minutes or until very thick and glossy. Combine sugars and add to pavlova mixture. Beat on high speed for 1 minute longer. Pile mixture onto prepared oven tray in a high dome shape. Using a sharp knife, create 2 or 3 grooves around the pavlova before cooking. Place in the centre shelf of the oven and reduce temperature to 120°C (100°C fan-forced). Bake for 1 hour, then turn oven off and allow pavlova to cool in the oven. Do not open the oven door during baking or cooling.
To make the orange cream: Using an electric mixer, beat cream until firm peaks form. Add orange zest. Beat on a low speed until just mixed through.
To decorate: Place pavlova on a serving plate. Top with orange cream. Place cherries on top of cream. Melt dark melts and drizzle on top, then scatter with hazelnuts.