Preheat oven to 160°C (do not use fan bake). Line an oven tray with baking paper and draw a 30cm circle on it (use a dinner plate as a stencil).
Separate egg whites from yolks. Place egg whites in a large, clean, dry bowl (or bowl of your stand mixer) and use electric beaters to whisk on medium speed until soft peaks form, 3-4 minutes. In a small bowl, combine water, vinegar, cornflour and a pinch of salt, until smooth. Add to egg whites and whisk briefly to combine.
Continue to whisk egg whites on medium speed, adding a tablespoon of caster sugar to the mix at a time; this should take about 10 minutes. Your meringue should look fluffy and silky.
Using a spoon, dollop meringue into 10 even sized mounds within the circle. Keep mounds attached. Use the back a spoon to create small dents in the top of each mound.
Turn oven down to 100° and bake pavlova for 120 minutes (DO NOT open oven door during this time). The pavlova may crack slightly, this is completely normal.
After 120 minutes, turn the oven off and leave pavlova in the oven to cool completely. Do this for 2 hours minimum, or overnight if possible. Put a sign on the door so you don’t forget it’s in there! Once completely cooled, the pavlova can be stored in an airtight container
When ready to serve, prep toppings. Place cream, vanilla extract and cardamon sugar mix in a large bowl or bowl of your stand mixer and use electric beaters to beat to soft peaks, about 3 minutes. Fold through yoghurt.
Roughly chop pistachios. Heat a dry frypan on medium-high heat. Toast pistachios, tossing often, about 3 minutes, until toasted.
Top each pavlova mound with cardamon cream, plum & rhubarb compote and toasted pistachios. Drizzle with honey.