Preheat oven to 150°C. Using a piece of kitchen paper and a little lemon juice, wipe around the interior of a large bowl or the bowl of freestanding mixer, along with the whisk attachments to ensure everything is completely grease free otherwise egg whites will not whip up properly. Line an oven tray with parchment paper.
Whisk the white until they reach soft peaks. Now add sugar, a tablespoonful at a time until all sugar is incorporated. When you have reached the correct consistency whites will have increased significantly in size, be glossy and stiff peaks remain when beater is removed.
Using a metal spoon or spatula carefully fold in the cornflour and vinegar.
Spoon the mixture onto the prepared baking sheet and form into a fat disc. Use a palette knife to smooth the sides and top.
Place in the oven, immediately turn the oven down to 120°C and bake for 1 hour.
When the pavlova has had its hour in the oven switch the oven off and allow the pavlova to cool completely in the oven. Do not open the oven door.
Meanwhile, Prepare the curd by scooping the pulp and seeds out of the passion fruit and placing in a small saucepan along with the lemon juice, water and sugar.
Whisk together over a high heat until it almost reaches boiling point.
Whisk the egg yolks in a bowl large enough to take the curd mixture. Then slowly add the hot curd mixture to the yolks whilst whisking constantly until all incorporated.
Pour back into the saucepan, gently whisk over a low heat, keeping the mixture moving, to prevent curdling until thickened. This will only take a couple of minutes then pour into a measuring jug to cool.
When cooled and ready to assemble. Whip cream softly.
Remove the cooled pavlova base from the oven turning out onto a plate upside down, so the marshmallowy base will receive the softly whipped cream.
Using a spatula spread the cream on top of the base then top this with the curd pushing it to the edges. If desired add a few raspberries to crown before serving.