Start by preheating your oven to 350ºF.
Prepare your cookie sheet by lining it with a piece of parchment paper. Using a pencil, trace a cup or biscuit cutter to outline evenly spaced tennis ball sized circles. You’ll want 12 circles roughly 3″ in diameter in total. Flip the parchment pencil side down on the pan. Alternatively: You can make one large pavlova about 12 inches in diameter, but I love the idea of a personal-sized treat – easy for serving!
Clean your stand mixer bowl with vinegar on a clean cloth to remove any fats from your bowl.
Add the egg whites to the clean bowl and start mixing with the whisk attachment on a medium speed (about 4 on the electric mixer) until soft peaks form. Patience is key! Do not increase the speed, this will incorporate air too quickly into the egg whites. Slow and steady wins the race.
Once soft peaks are formed, slowly sift in the powdered sugar just a little bit at a time. Mixing well between additions on medium speed. Make sure the sugar is fully dissolved in the egg whites with each addition of sugar. Scrape the bowl often as you go to ensure all of the sugar granules are dissolved fully. Continue to whip the mixture until glossy, stiff peaks form.
In a small bowl, whisk the white vinegar, cornstarch, and vanilla until lump free.
Add the vinegar mixture to the egg whites on medium speed for about 30 seconds, you can bump up the speed for the last 15 seconds to whip the peaks.
Scoop the meringue into small heaps on your traced circles on your parchment paper. You can use a spatula or the back of the spoon to shape them into little mountains leaving a small crater in the center.
Decrease the oven temperature to 225º
Pop your pavlovas in the oven and pray to the meringue gods that they turn out! ;)
Bake for 90 minutes, do not open the oven door! Resist the temptation (because they will collapse). Once the 90 minutes are up, turn off the oven and allow the pavlovas to cool completely in the oven. I repeat, don't open the oven door!
While the pavlovas are baking prepare your strawberry filling. Start by washing and cutting your strawberries. You can macerate some of the berries as well with a wooden spoon or muddler.
Stir in the ¼ cup of sugar, balsamic glaze, lemon juice, zest, and some mint leaves. Let sit while the pavlova cooks.
Right before serving, whip the heavy cream and powdered sugar together until stiff peaks form.
After the pavlovas are fully cooled, remove them from the oven and place the on a serving dish. Layer in some whipped cream, and top with a spoon full of strawberry mixture. Garnish with a bit of fresh mint and lemon zest and serve!