Preheat the oven to 300F and line a baking sheet with parchment paper. Trace an 8-inch circle on the parchment paper - we will use this as a guide. 

In the bowl of a stand mixer fitted with the whisk attachment on medium-high speed, whisk the egg whites and salt until medium-stiff peaks.

Add sugar slowly on low speed. Once incorporated increase speed to medium-high and continue whisking until stiff peaks form. 

Fold in the vinegar, cornstarch and vanilla.

Transfer mixture into the circle traced on the baking sheet and start shaping your pavlova using an angled spatula.

Bake for 30 minutes on 300F, then lower temperature to 275F and bake for another 45 minutes.

Allow the meringue to cool in the oven for another hour. Do not open the door or the it will crack more.

In a bowl of a stand mixer fitted with the whisk attachment on high speed, add in the heavy cream and whisk until soft peaks form. Slowly add the powdered sugar and continue mixing until combined. Next, add the vanilla extract and whip until stiff peaks form.