Get ready: Preheat your oven to 350 degrees. Remove eggs from fridge and allow to warm to room temp (about 5 minutes). Line a baking (cookie) sheet with parchment paper, and set aside. Fit your electric mixer with the whisk attachment.
In your mixer bowl, beat egg whites together with salt until glossy peaks form. Slowly add in the sugar, and continue whipping until stiff peaks form. Turn off mixer, remove bowl.
Mix cornstarch and matcha powder together, ensuring no lumps of matcha remain. Carefully fold into meringue. Sprinkle vanilla and vinegar over meringue, gently fold until well combined.
Heap meringue onto the center of your baking sheet. Use a spatula to spread the meringue out to approximately an 8-9″ circle. I like to have my meringue a fairly even depth throughout – some like a mound, some like it to be a little concave. If you want to get really fancy, put the meringue into a pastry bag and pipe it out as a mass of swirls that form your 8? circle! It’s really up to you!
Put the baking sheet into your oven, and turn the temperature down to 250 degrees. Bake for 1 hour and 20 minutes. Once your timer goes off, turn the oven off and let the meringue cool in the oven for several hours. The baking of the meringue can be done the day before, if needed!
Just before serving, whip together the heavy cream, sugar, and matcha powder until it reaches desired thickeness.
Mound the whipped cream on your pavlova, and top with fruit. Serve immediately!