Pavlova meringue :

1. Prepare a sheet of parchment paper and using a large plate draw 1 large circle of 8 inches / 20 cm. 
2. Place the egg whites and vanilla extra in the bowl of your stand mixer with the whisk attachment and whip on low speed for 5 minutes until the whites form bubbles.
3. Then switch to medium speed and pulse again for about 5 minutes until the whites form soft peaks.
4. Then switch to low speed and gradually add the powdered sugar a spoonful at a time until it is well dissolved in the egg whites. (for about 10 minutes)
5. Once you have incorporated all the sugar, switch to medium speed and mix for another 10 minutes.
6. Check to see if the sugar is dissolved by touching the meringue between your fingers, if you still feel grains of sugar, continue mixing for another 5-10 minutes.
7. Add the cornstarch, and white vinegar and mix on high speed for 1 - 2 minutes. The meringue should be firm with stiff peaks and shiny.
8. Place all the meringue on the baking sheet covered with the parchment paper and shape the pavlova.
9. Preheat your oven to 248°F / 120°C and place the pavlova halfway in the oven.
10. Lower the temperature to 230°F/110°C and bake for about 90 minutes without opening the oven door.
11. At the end of the cooking time, turn off the oven and leave the pavlova in the oven for at least 1 hour or even overnight.

Mascarpone whipped cream :

1. Place the heavy cream, confectioner's sugar, mascarpone, and vanilla extract in a medium bowl and beat with a hand mixer for about 5 minutes at a slow speed, then gradually increase the speed until you have a stiff cream.
2. Place the pavlova carefully on a large plate or serving dish.
3. Top with a generous layer of mascarpone whipped cream.
4. Decorate with fresh berries or fruits.
5. Serve at the last minute with a fruit coulis and sprinkle with confectioner's sugar.